以下是一些RT-PCR的技术操作及相应文献参考:有意者可从中得到一些启示。
. cuturl('http://www.research.umbc.edu/~jwolf/m12.htm')(UMBC)
First strand synthesis and subsequent PCR amplification. Based on LTI protocol
. cuturl('http://www.nwfsc.noaa.gov/protocols/revtrpcr.html')(NWFSC)
Procedure for cDNA synthesis on dynabeads oligo(dT)25
. cuturl('http://gause.usuhs.mil/rt.html')(Cause's Lab)
Detailed protocol for RT and PCR
. cuturl('http://wheat.pw.usda.gov/homepage/lazo/methods/lazo/revtrpcr.html')(Lazo Lab)
First strand cDNA synthesis and PCR amplification
. cuturl('http://www.biol.rug.nl/lacto/protocols/superscript.html')
Procedure either for RT-PCR and primer extension. For primer extension, just add hot dATP
. cuturl('http://www.microbiology.med.umn.edu/immunology/cDNA_RT-PCR.html')(Immunology Resource)
CDNA synthesis from mRNA and subsequent PCR amplification
. cuturl('http://zapruder.pds.med.umich.edu/users/Frank/HepC/HepC.html')(Hans Popper)
This protocol is for the non-isotopic detection of hepatitis C RNA and albumin mRNA (as an internal control) from 4 micron sections of formalin-fixed, paraffin-embedded liver biopsies by RT-PCR. The procedure for RNA extraction from formalin fixed paraffin embedded section and PCR amplification is described. 作者: 荷塘青蛙! 时间: 2011-9-6 15:25
sorry i can not type chinese now.
it does not need RNase-H digestion,beside the single strand of cDNA is different. the Pcr procedure is changeable and not standerd in dfferent time. so u should do inner control every time and caculate the ratio of target gene and housekepping gene. 作者: 果冻也酸 时间: 2011-9-6 16:15
sorry cannot type chinese now. i maybe write in chinese later.
for <Biowind>
of couse it should determined the amount of RNA. but it not for the quantitity of the PCR. it just was convienent to guess the amount ot the template<(for RT and PCR) and bettrer for publication and editor if he don not know the preocedure much. but the amount just using "accurate piptte" is wrong. it shoud be remembered to do the inner control of housekeeping gene everytime. 作者: 椰子叶子 时间: 2011-9-6 16:22
sorry i can not type chinese now.
it does not need RNase-H digestion,beside the single strand of cDNA is different. the Pcr procedure is changeable and not standerd in dfferent time. so u should do inner control every time and caculate the ratio of target gene and housekepping gene. 作者: =菓子= 时间: 2011-9-6 16:32
sorry cannot type chinese now. i maybe write in chinese later.
for <Biowind>
of couse it should determined the amount of RNA. but it not for the quantitity of the PCR. it just was convienent to guess the amount ot the template<(for RT and PCR) and bettrer for publication and editor if he don not know the preocedure much. but the amount just using "accurate piptte" is wrong. it shoud be remembered to do the inner control of housekeeping gene everytime. 作者: fangxiang 时间: 2011-9-6 17:09
in my opinin it is not so excellent to design the primers sith software. and according the main principle of designation and using your naked esys. and also do not beleieve the reference always.
as for as varient,i do not know what u mean. the SNP or variant transcripition? please refer my
cuturl('http://www.dxy.cn/bbs/post/view?bid=67&id=166687&sty=1&tpg=1&age=-1')
the primer,especialy the last nucleotide, i think, should better at the position of firdt nucleotide of 3 codon,if u select the ORF as the target sequence. 作者: 明天的明天 时间: 2011-9-7 10:58
question 1: of course.
question 2: of course. if some guys' primers is different i think it must onlyy one or two nucleotides difference. and he must use the varient as the template. there are some different mRNA sequences in the GenBank, the causes are many, for example, the wrong sequencing and the varient gene itself.作者: fangxiang 时间: 2011-9-7 11:00
if u refer '单链构象多态性' as SNP,it is wrong. the former is SSCP and the latter is single nucleotide polymorhism.
在前者存在的情况下,是不是要尽量避免把引物设计在snp的差异位点上. of course the primers are on the upstrem and doownstream respectiverly.
在Genebank中一段gene的cds总是小于full length,那么是不是大多数cds都是保守的,可否只扩增cds中间的序列来消除transcription variant 的影响?according to the 5' and 3' UTR the ORF comparely conserve esüecially in one gene family or superfamily. but for on cetain gene only the domain is conserve,for exaample, in different specie. but the conservation of domain is refer to protein rather than gene, for example, the third nucleotide of the coden may be vatient.
另外是不是pcr引物设计时要很注意待扩增区域的gc含量是否均匀,如何判别均匀与否,如果不是很均匀,是不是不好控制退火温度?如果实在是不均匀,在反应时如何改进实验条件?refer to the textbook.
难道genebank中的不正确的序列还没有被删除吗?of course. u can create a sequence to input also 作者: 岸上的鱼 时间: 2011-9-7 11:02
阿拉蕾:
能否冒昧地问一下,你能帮我参考一下吗。我要做的 是survivin 基因,我在medline上查得LOCUS BIRC5 1619 bp mRNA linear PRI 31-OCT-2000
DEFINITION Homo sapiens baculoviral IAP repeat-containing 5 (survivin)
(BIRC5), mRNA.
ACCESSION NM_001168
VERSION NM_001168.1 GI:4502144
KEYWORDS .
SOURCE Homo sapiens (human)
ORGANISM Homo sapiens
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
Mammalia; Eutheria; Primates; Catarrhini; Hominidae; Homo.
REFERENCE 1 (bases 1 to 1619)
AUTHORS Altieri,D.C.
TITLE Molecular cloning of effector cell protease receptor-1, a novel
cell surface receptor for the protease factor Xa
JOURNAL J. Biol. Chem. 269 (5), 3139-3142 (1994)
MEDLINE 94148797
PUBMED 8106347
REFERENCE 2 (bases 1 to 1619)
AUTHORS Altieri,D.C.
TITLE Splicing of effector cell protease receptor-1 mRNA is modulated by
an unusual retained intron
JOURNAL Biochemistry 33 (46), 13848-13855 (1994)
MEDLINE 95034823
PUBMED 7947793
REFERENCE 3 (bases 1 to 1619)
AUTHORS Ambrosini,G., Adida,C. and Altieri,D.C.
TITLE A novel anti-apoptosis gene, survivin, expressed in cancer and
lymphoma
JOURNAL Nat. Med. 3 , 917-921 (1997)作者: 喵咪 时间: 2011-9-7 14:42
MEDLINE 97398388
PUBMED 9256286
REFERENCE 4 (bases 1 to 1619)
AUTHORS Ambrosini,G., Adida,C., Sirugo,G. and Altieri,D.C.
TITLE Induction of apoptosis and inhibition of cell proliferation by
survivin gene targeting
JOURNAL J. Biol. Chem. 273 (18), 11177-11182 (1998)
MEDLINE 98225200
PUBMED 9556606
REFERENCE 5 (bases 1 to 1619)
AUTHORS Li,F., Ambrosini,G., Chu,E.Y., Plescia,J., Tognin,S.,
Marchisio,P.C. and Altieri,D.C.
TITLE Control of apoptosis and mitotic spindle checkpoint by survivin
JOURNAL Nature 396 (6711), 580-584 (1998)
MEDLINE 99075336
PUBMED 9859993
COMMENT REVIEWED REFSEQ: This record has been curated by NCBI staff. The
reference sequence was derived from U75285.1.
Summary: The protein encoded by this gene is an apoptosis inhibitor
that is expressed during the G2/M phase of the cell cycle. BIRC5
associates with the microtubules of the mitotic spindle and any
disruption results in the loss of apoptosis activity.
COMPLETENESS: complete on the 3' end.
FEATURES Location/Qualifiers
source 1..1619
/organism="Homo sapiens"
/db_xref="taxon:9606"
/chromosome="17"
/map="17q25"
gene 1..1619
/gene="BIRC5"
/note="synonym: API4"
/db_xref="LocusID:332"
/db_xref="MIM:603352"
CDS 50..478
/gene="BIRC5"
/note="apoptosis inhibitor 4; survivin"
/codon_start=1
/product="baculoviral IAP repeat-containing protein 5"
/protein_id="NP_001159.1"
/db_xref="GI:4502145"
/db_xref="LocusID:332"
/db_xref="MIM:603352"
/translation="MGAPT LPPAW QPFLK DHRIS TFKNW PFLEG CACTP ERMAE AGFI
H CPTEN EPDLA QCFFC FKELE GWEPD DDPIE EHKKH SSGCA FLSVK KQFEE LTLGE FL
KLD RERAK NKIAK ETNNK KKEFE ETAKK VRRAI EQLAA MD"
misc_feature 89..310
/gene="BIRC5"
/note="BIR; Region: Baculoviral inhibition of apoptosis
protein repeat"
/db_xref="CDD:BIR"
misc_feature 101..310
/gene="BIRC5"
/note="BIR; Region: Inhibitor of Apoptosis domain"作者: 喵咪 时间: 2011-9-7 14:42
genomic sequence of your gene.
just possiblity. another possiblity is the gene of superfamily.
but i think former is possibe
CHECK THE PRIMERS ON THE GENOIMC OF YOUR GENE NOT ALL GENOMICS 作者: 天蓝蓝 时间: 2011-9-7 14:53
check the primers if it is on the exons and check if the length between the primers is equal to the length u have amplified.
or using DNaseI treatment before RT to test. 作者: 天蓝蓝 时间: 2011-9-7 14:54
check the genomics, not only mRNA. how many exons does this gene have? how long between the 2 primers in genomics? if it is 2kb, ithat is the problem. u might mix the genomics in the RNA. of course it just a guess. so that is why i suggest u check it first. 作者: 天蓝蓝 时间: 2011-9-7 14:54
actually, there are indeed other RNA during the PCR if u use total RNA<i think so, because nowaday seldom using mRNA) as the template during the RT. the tRNA and rRNA are still mixed in the cDNA.
but what i mean is not rRNA and tRNA. I just told u that the genomic DNA maybe mix in the RNA. and so i ask how many exons this gene has. 作者: 天蓝蓝 时间: 2011-9-7 14:59
各位高手,不好意思,我是PCR新手,请教几个愚蠢的问题:
内参照有种属差异吗?如大鼠、小鼠。
yes.
用Trizol处理的标本-70度可保存多久?
samles or RNA? ABOUT 1 YEAR. better not too longer.
内参与目的片断可以同时PCR吗?有何要点?
better not.
LOCUS NM_001964 3136 bp mRNA linear PRI 01-JUN-2003
DEFINITION Homo sapiens early growth response 1 (EGR1), mRNA.
ACCESSION NM_001964
VERSION NM_001964.2 GI:31317226
KEYWORDS .
SOURCE Homo sapiens (human)
MM EGR-1,NM 007913是
LOCUS NM_007913 4494 bp mRNA linear ROD 07-APR-2003
DEFINITION Mus musculus early growth response 1 (Egr1), mRNA.
ACCESSION NM_007913
VERSION NM_007913.2 GI:24475900
KEYWORDS .
SOURCE Mus musculus (house mouse)
eeflying is right.
no necessary to wash.
nothing in the trace medium will interfere the RNA.
think about it, need we wash the specomen of the surgery operation? 作者: panda王 时间: 2011-9-7 15:31
I am from Singapore, computer can see Chinese but cannot input Chinese characteres, so I write in English. Sorry for inconvenience.
I need to clone a long gene ~3.5kb. I extract total RNA then reverse transcibe to cDNA, then PCR with various conditions, with betaine, dmso, different mgcl2, different annealing temperature with no success, using long dna polymerase. However I can PCR Gapdh.
I doubt it is a reverse transcription problem. Can anyone suggest what to do to RT the long RNA ~3.5kb?
Did anyone have any ever add DMSO or other additive into reverst transcription?
it is not from genomics. think about it, if from the genomic, it should be longer than that from cDNA. it is from the RNA itself. please check my BBS in DXY. i have said that several times. the Taq has the ability to amplify directly from the RNA!
best wishes,作者: mogu 时间: 2011-9-7 15:49
refer to
cuturl('http://www.dxy.cn/bbs/post/view?bid=67&id=166687&sty=1&tpg=1&age=-1') 作者: mogu 时间: 2011-9-7 15:50
看了你下面给我的回答,我不明白你的第二句话。
“ because for RT, u will not ampilifiy it until platue phase.”
你是指PCR的平台期才可能以RNA为模板,taq酶合成目的条带吗?为什么呢?有什么理论依据吗?
非常感谢!作者: mogu 时间: 2011-9-7 15:50
看了你下面给我的回答,我不明白你的第二句话。
“ because for RT, u will not ampilifiy it until platue phase.”
你是指PCR的平台期才可能以RNA为模板,taq酶合成目的条带吗?为什么呢?有什么理论依据吗?
非常感谢!作者: 阿拉蕾 时间: 2011-9-7 15:50
trace RNA, no necissary to care about it in the caculation and experiment. because for RT, u will not ampilifiy it until platue phase. 作者: 阿拉蕾 时间: 2011-9-7 15:51
Hi all,
I am from Singapore, computer can see Chinese but cannot input Chinese characteres, so I write in English. Sorry for inconvenience.
I need to clone a long gene ~3.5kb. I extract total RNA then reverse transcibe to cDNA, then PCR with various conditions, with betaine, dmso, different mgcl2, different annealing temperature with no success, using long dna polymerase. However I can PCR Gapdh.
I doubt it is a reverse transcription problem. Can anyone suggest what to do to RT the long RNA ~3.5kb?
Did anyone have any ever add DMSO or other additive into reverst transcription?
这是我的基因序列,各位帮我看看引物设计的有问题吗?
: BC034148. Homo sapiens, bac...[gi:21707886] Links
LOCUS BC034148 1643 bp mRNA linear PRI 08-JUL-2002
DEFINITION Homo sapiens, baculoviral IAP repeat-containing 5 (survivin), clone
MGC:32768 IMAGE:4656567, mRNA, complete cds.
ACCESSION BC034148
VERSION BC034148.1 GI:21707886
KEYWORDS MGC.
SOURCE Homo sapiens (human)
ORGANISM Homo sapiens
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
Mammalia; Eutheria; Primates; Catarrhini; Hominidae; Homo.
REFERENCE 1 (bases 1 to 1643)
AUTHORS Strausberg,R.
TITLE Direct Submission
JOURNAL Submitted (02-JUL-2002) National Institutes of Health, Mammalian
Gene Collection (MGC), Cancer Genomics Office, National Cancer
Institute, 31 Center Drive, Room 11A03, Bethesda, MD 20892-2590,
USA
REMARK NIH-MGC Project URL: cuturl('http://mgc.nci.nih.gov')
COMMENT Contact: MGC help desk
Email: cgapbs-r@mail.nih.gov
Tissue Procurement: ATCC
cDNA Library Preparation: CLONTECH Laboratories, Inc.
cDNA Library Arrayed by: The I.M.A.G.E. Consortium (LLNL)
DNA Sequencing by: Sequencing Group at the Stanford Human Genome
Center, Stanford University School of Medicine, Stanford, CA 94305
Web site: cuturl('http://www-shgc.stanford.edu')
Contact: (Dickson, Mark) mcd@paxil.stanford.edu
Dickson, M., Schmutz, J., Grimwood, J., Rodriquez, A., and Myers,
R. M.作者: HOT兔 时间: 2011-9-7 16:08
RT-PCR (reverse transcription-polymerase chain reaction) is the most sensitive technique for mRNA detection and quantitation currently available. Compared to the two other commonly used techniques for quantifying mRNA levels, Northern blot analysis and RNase protection assay, RT-PCR can be used to quantify mRNA levels from much smaller samples. In fact, this technique is sensitive enough to enable quantitation of RNA from a single cell.
This article first discusses the advantages of real-time RT-PCR compared to end-point methods. This discussion is followed by a description of the different methods for quantitating gene expression by real-time RT-PCR with respect to the different chemistries available, the quantitation methods used and the instrumentation options available. Subsequently, the “traditional” methods of quantitating gene expression by RT-PCR, i.e. end-point techniques, are presented.
Why Real-Time RT-PCR?
Over the last several years, the development of novel chemistries and instrumentation platforms enabling detection of PCR products on a real-time basis has led to widespread adoption of real-time RT-PCR as the method of choice for quantitating changes in gene expression. Furthermore, real-time RT-PCR has become the preferred method for validating results obtained from array analyses and other techniques that evaluate gene expression changes on a global scale.
To truly appreciate the benefits of real-time PCR, a review of PCR fundamentals is necessary. At the start of a PCR reaction, reagents are in excess, template and product are at low enough concentrations that product renaturation does not compete with primer binding, and amplification proceeds at a constant, exponential rate. The point at which the reaction rate ceases to be exponential and enters a linear phase of amplification is extremely variable, even among replicate samples, but it appears to be primarily due to product renaturation competing with primer binding (since adding more reagents or enzyme has little effect). At some later cycle the amplification rate drops to near zero (plateaus), and little more product is made.
For the sake of accuracy and precision, it is necessary to collect quantitative data at a point in which every sample is in the exponential phase of amplification (since it is only in this phase that amplification is extremely reproducible). Analysis of reactions during exponential phase at a given cycle number should theoretically provide several orders of magnitude of dynamic range. Rare targets will probably be below the limit of detection, while abundant targets will be past the exponential phase. In practice, a dynamic range of 2-3 logs can be quantitated during end-point relative RT-PCR. In order to extend this range, replicate reactions may be performed for a greater or lesser number of cycles, so that all of the samples can be analyzed in the exponential phase.
Real-time PCR automates this otherwise laborious process by quantitating reaction products for each sample in every cycle. The result is an amazingly broad 107-fold dynamic range, with no user intervention or replicates required. Data analysis, including standard curve generation and copy number calculation, is performed automatically. With increasing numbers of labs and core facilities acquiring the instrumentation required for real-time analysis, this technique is becoming the dominant RT-PCR-based quantitation technique.作者: 椰子叶子 时间: 2011-9-10 15:59
Real-Time PCR Chemistries
Currently four different chemistries, TaqMan® (Applied Biosystems, Foster City, CA, USA), Molecular Beacons, Scorpions® and SYBR® Green (Molecular Probes), are available for real-time PCR. All of these chemistries allow detection of PCR products via the generation of a fluorescent signal. TaqMan probes, Molecular Beacons and Scorpions depend on Förster Resonance Energy Transfer (FRET) to generate the fluorescence signal via the coupling of a fluorogenic dye molecule and a quencher moeity to the same or different oligonucleotide substrates. SYBR Green is a fluorogenic dye that exhibits little fluorescence when in solution, but emits a strong fluorescent signal upon binding to double-stranded DNA.
TaqMan Probes
TaqMan probes depend on the 5'- nuclease activity of the DNA polymerase used for PCR to hydrolyze an oligonucleotide that is hybridized to the target amplicon. TaqMan probes are oligonucleotides that have a fluorescent reporter dye attached to the 5' end and a quencher moeity coupled to the 3' end. These probes are designed to hybridize to an internal region of a PCR product. In the unhybridized state, the proximity of the fluor and the quench molecules prevents the detection of fluorescent signal from the probe. During PCR, when the polymerase replicates a template on which a TaqMan probe is bound, the 5'- nuclease activity of the polymerase cleaves the probe. This decouples the fluorescent and quenching dyes and FRET no longer occurs. Thus, fluorescence increases in each cycle, proportional to the amount of probe cleavage
Well-designed TaqMan probes require very little optimization. In addition, they can be used for multiplex assays by designing each probe with a spectrally unique fluor/quench pair. However, TaqMan probes can be expensive to synthesize, with a separate probe needed for each mRNA target being analyzed.
Molecular Beacons
Like TaqMan probes, Molecular Beacons also use FRET to detect and quantitate the synthesized PCR product via a fluor coupled to the 5' end and a quench attached to the 3' end of an oligonucleotide substrate. Unlike TaqMan probes, Molecular Beacons are designed to remain intact during the amplification reaction, and must rebind to target in every cycle for signal measurement. Molecular Beacons form a stem-loop structure when free in solution. Thus, the close proximity of the fluor and quench molecules prevents the probe from fluorescing. When a Molecular Beacon hybridizes to a target, the fluorescent dye and quencher are separated, FRET does not occur, and the fluorescent dye emits light upon irradiation.
Molecular Beacons, like TaqMan probes, can be used for multiplex assays by using spectrally separated fluor/quench moieties on each probe. As with TaqMan probes, Molecular Beacons can be expensive to synthesize, with a separate probe required for each target.作者: 椰子叶子 时间: 2011-9-10 15:59
Scorpions
With Scorpion probes, sequence-specific priming and PCR product detection is achieved using a single oligonucleotide. The Scorpion probe maintains a stem-loop configuration in the unhybridized state. The fluorophore is attached to the 5' end and is quenched by a moiety coupled to the 3' end. The 3' portion of the stem also contains sequence that is complementary to the extension product of the primer. This sequence is linked to the 5' end of a specific primer via a non-amplifiable monomer. After extension of the Scorpion primer, the specific probe sequence is able to bind to its complement within the extended amplicon thus opening up the hairpin loop. This prevents the fluorescence from being quenched and a signal is observed.
SYBR Green
SYBR Green provides the simplest and most economical format for detecting and quantitating PCR products in real-time reactions. SYBR Green binds double-stranded DNA, and upon excitation emits light. Thus, as a PCR product accumulates, fluorescence increases. The advantages of SYBR Green are that it is inexpensive, easy to use, and sensitive. The disadvantage is that SYBR Green will bind to any double-stranded DNA in the reaction, including primer-dimers and other non-specific reaction products, which results in an overestimation of the target concentration. For single PCR product reactions with well designed primers, SYBR Green can work extremely well, with spurious non-specific background only showing up in very late cycles.
SYBR Green is the most economical choice for real-time PCR product detection. Since the dye binds to double-stranded DNA, there is no need to design a probe for any particular target being analyzed. However, detection by SYBR Green requires extensive optimization. Since the dye cannot distinguish between specifc and non-specifc product accumulated during PCR, follow up assays are needed to validate results.
Real-time Reporters for Multiplex PCR
TaqMan probes, Molecular Beacons and Scorpions allow multiple DNA species to be measured in the same sample (multiplex PCR), since fluorescent dyes with different emission spectra may be attached to the different probes. Multiplex PCR allows internal controls to be co-amplified and permits allele discrimination in single-tube, homogeneous assays. These hybridization probes afford a level of discrimination impossible to obtain with SYBR Green, since they will only hybridize to true targets in a PCR and not to primer-dimers or other spurious products. 作者: 椰子叶子 时间: 2011-9-10 16:00
Quantitation of Results
Two strategies are commonly employed to quantify the results obtained by real-time RT-PCR; the standard curve method and the comparative threshold method. These are discussed briefly below.
Standard Curve Method
In this method, a standard curve is first constructed from an RNA of known concentration. This curve is then used as a reference standard for extrapolating quantitative information for mRNA targets of unknown concentrations. Though RNA standards can be used, their stability can be a source of variability in the final analyses. In addition, using RNA standards would involve the construction of cDNA plasmids that have to be in vitro transcribed into the RNA standards and accurately quantitated, a time-consuming process. However, the use of absolutely quantitated RNA standards will help generate absolute copy number data.
In addition to RNA, other nucleic acid samples can be used to construct the standard curve, including purified plasmid dsDNA, in vitro generated ssDNA or any cDNA sample expressing the target gene. Spectrophotometric measurements at 260 nm can be used to assess the concentration of these DNAs, which can then be converted to a copy number value based on the molecular weight of the sample used. cDNA plasmids are the preferred standards for standard curve quantitation. However, since cDNA plasmids will not control for variations in the efficiency of the reverse transcription step, this method will only yield information on relative changes in mRNA expression. This, and variation introduced due to variable RNA inputs, can be corrected by normalization to a housekeeping gene.
Comparative Ct Method
Another quantitation approach is termed the comparative Ct method. This involves comparing the Ct values of the samples of interest with a control or calibrator such as a non-treated sample or RNA from normal tissue. The Ct values of both the calibrator and the samples of interest are normalized to an appropriate endogenous housekeeping gene.
The comparative Ct method is also known as the 2–[delta][delta]Ct method, where
Here, [delta]CT,sample is the Ct value for any sample normalized to the endogenous housekeeping gene and [delta]Ct, reference is the Ct value for the calibrator also normalized to the endogenous housekeeping gene.
For the [delta][delta]Ct calculation to be valid, the amplification efficiencies of the target and the endogenous reference must be approximately equal. This can be established by looking at how [delta]Ct varies with template dilution. If the plot of cDNA dilution versus delta Ct is close to zero, it implies that the efficiences of the target and housekeeping genes are very similar. If a housekeeping gene cannot be found whose amplification efficiency is similar to the target, then the standard curve method is preferred.
Instrumentation for Real-Time PCR
Real-time PCR requires an instrumentation platform that consists of a thermal cycler, a computer, optics for fluorescence excitation and emission collection, and data acquisition and analysis software. These machines, available from several manufacturers, differ in sample capacity (some are 96-well standard format, others process fewer samples or require specialized glass capillary tubes), method of excitation (some use lasers, others broad spectrum light sources with tunable filters), and overall sensitivity. There are also platform-specific differences in how the software processes data. Real-time PCR machines are not inexpensive, currently about $25K - $95K, but are well within purchasing reach of core facilities or labs that have the need for high throughput quantitative analysis. For a comprehensive list of real-time thermal cyclers please see the weblink at the end of this article.作者: 椰子叶子 时间: 2011-9-10 16:00
Tools for Real-Time RT-PCR
Ambion’s MessageSensor™ RT Kit includes an RNase H+ MMLV RT that clearly outperforms MMLV RT enzymes that have abolished RNase H activity in real-time RT-PCR experiments. Unlike many other qRT-PCR kits, MessageSensor includes a total RNA control, a control human GAPDH primer set, RNase inhibitor, and nucleotides, as well as a buffer additive that enables detection with SYBR® Green dye.
The Cells-to-cDNA™ II Kit produces cDNA from cultured mammalian cells in less than 2 hours. No RNA isolation is required. This kit is ideal for those who want to perform reverse transcription reactions on small numbers of cells, numerous cell samples, or for scientists who are unfamiliar with RNA isolation. Ambion's Cells-to-cDNA II Kit contains a novel Cell Lysis Buffer that inactivates endogenous RNases without compromising downstream enzymatic reactions. After inactivation of RNases, the cell lysate can be directly added to a cDNA synthesis reaction. Cells-to-cDNA II is compatible with both one-step and two-step real-time RT-PCR protocols.
Genomic DNA contamination can lead to false positive RT-PCR results. Ambion offers a variety of tools for eliminating genomic DNA contamination from RNA samples prior to RT-PCR. Ambion’s DNA-free™ DNase Treatment and Removal Reagents are designed for removing contaminating DNA from RNA samples and for the removal of DNase after treatment without Proteinase K treatment and organic extraction. In addition, Ambion has also developed TURBO™ DNase, a hyperactive enzyme engineered from wild-type bovine DNase. The proficiency of TURBO DNase in binding very low concentrations of DNA means that the enzyme is particularly effective in removing trace quantities of DNA contamination.
Ambion now also offers an economical alternative to the high cost of PCR reagents for the ABI 7700 and other 0.2 ml tube-based real-time instruments. SuperTaq™ Real-Time performs as well or better than the more expensive alternatives, and includes dNTPs and a Reaction Buffer optimized for SYBR Green, TaqMan, and Molecular Beacon chemistries.
End-Point RT-PCR: Relative vs. Competitive vs. Comparative
In spite of the rapid advances made in the area of real-time PCR detection chemistries and instrumentation, end-point RT-PCR still remains a very commonly used technique for measuring changes in gene-expression in small sample numbers.
End-point RT-PCR can be used to measure changes in expression levels using three different methods: relative, competitive and comparative. The most commonly used procedures for quantitating end-point RT-PCR results rely on detecting a fluorescent dye such as ethidium bromide, or quantitation of P32-labeled PCR product by a phosphorimager or, to a lesser extent, by scintillation counting.作者: 椰子叶子 时间: 2011-9-10 16:00
Relative quantitation compares transcript abundance across multiple samples, using a co-amplified internal control for sample normalization. Results are expressed as ratios of the gene-specific signal to the internal control signal. This yields a corrected relative value for the gene-specific product in each sample. These values may be compared between samples for an estimate of the relative expression of target RNA in the samples; for example, 2.5-fold more IL-12 in sample 2 than in sample 1.
Absolute quantitation, using competitive RT-PCR, measures the absolute amount (e.g., 5.3 x 105 copies) of a specific mRNA sequence in a sample. Dilutions of a synthetic RNA (identical in sequence, but slightly shorter than the endogenous target) are added to sample RNA replicates and are co-amplified with the endogenous target. The PCR product from the endogenous transcript is then compared to the concentration curve created by the synthetic "competitor RNA."
Comparative RT-PCR mimics competitive RT-PCR in that target message from each RNA sample competes for amplification reagents within a single reaction, making the technique reliably quantitative. Because the cDNA from both samples have the same PCR primer binding site, one sample acts as a competitor for the other, making it unnecessary to synthesize a competitor RNA sequence.
Both relative and competitive RT-PCR quantitation techniques require pilot experiments. In the case of relative RT-PCR, pilot experiments include selection of a quantitation method and determination of the exponential range of amplification for each mRNA under study. For competitive RT-PCR, a synthetic RNA competitor transcript must be synthesized and used in pilot experiments to determine the appropriate range for the standard curve. Comparative RT-PCR yields similar sensitivity as relative and competitive RT-PCR, but requires significantly less optimization and does not require synthesis of a competitor.作者: 椰子叶子 时间: 2011-9-10 16:01
Relative RT-PCR
Relative RT-PCR uses primers for an internal control that are multiplexed in the same RT-PCR reaction with the gene specific primers. Internal control and gene-specific primers must be compatible — that is, they must not produce additional bands or hybridize to each other. The expression of the internal control should be constant across all samples being analyzed. Then the signal from the internal control can used to normalize sample data to account for tube-to-tube differences caused by variable RNA quality or RT efficiency, inaccurate quantitation or pipetting. Common internal controls include ß-actin and GAPDH mRNAs and 18S rRNA. Unlike Northerns and nuclease protection assays, where an internal control probe is simply added to the experiment, the use of internal controls in relative RT-PCR requires substantial optimization.
For relative RT-PCR data to be meaningful, the PCR reaction must be terminated when the products from both the internal control and the gene of interest are detectable and are being amplified within exponential phase (see Determining Exponential Range in PCR). Because internal control RNAs are typically constituitively expressed housekeeping genes of high abundance, their amplification surpasses exponential phase with very few PCR cycles. It is therefore difficult to identify compatible exponential phase conditions where the PCR product from a rare message is detectable. Detection methods with low sensitivity, like ethidium bromide staining of agarose gels, are therefore not recommended. Detecting a rare message while staying in exponential range with an abundant message can be achieved several ways: 1) by increasing the sensitivity of product detection, 2) by decreasing the amount of input template in the RT or PCR reactions and/or 3) by decreasing the number of PCR cycles.
Ambion recommends using 18S rRNA as an internal control because it shows less variance in expression across treatment conditions than ß-actin and GAPDH (see Choosing and Validating Your Internal Control for more information). However, because of its abundance, it is difficult to detect the PCR product for rare messages in the exponential phase of amplification of 18S rRNA. Ambion's patented Competimer™ Technology solves this problem by attenuating the 18S rRNA signal even to the level of rare messages. Attenuation results from the use of competimers — primers identical in sequence to the functional 18S rRNA primers but that are "blocked" at their 3'-end and, thus, cannot be extended by PCR. Competimers and primers are mixed at various ratios to reduce the amount of PCR product generated from 18S rRNA. Figure 1 illustrates that 18S rRNA primers without competimers cannot be used as an internal control because the 18S rRNA amplification overwhelms that of clathrin (compare panels A and . Mixing primers with competimers at a 3:7 ratio attenuates the 18S rRNA signal, making 18S rRNA a practical internal control (panel C).
Figure 1. Ambion's QuantumRNA™ Technology in Multiplex Quantitative RT-PCR using 18S rRNA as an Internal Control. RT-PCR reactions on brain, embryo, liver, and spleen total RNA using A) primers for clathrin, primers for clathrin and 18S, or C) primers for clathrin, 18S rRNA primers and 18S rRNA Competimers. Note that without Competimers, 18S cannot be used as an internal control because of its high abundance (. Addition of Competimers (C) makes multiplex PCR possible, providing sample-to-sample relative quantitation. 作者: 椰子叶子 时间: 2011-9-10 16:01
Ambion's QuantumRNA 18S Internal Standards contain 18S rRNA primers and competimers designed to amplify 18S rRNA in all eukaryotes. The Universal 18S Internal Standards function across the broadest range of organisms including plants, animals and many protozoa. The Classic I and Classic II 18S Internal Standards can be used with any vertebrate RNA sample. All 18S Internal Standards work well in multiplex RT-PCR. These kits also include control RNA and an Instruction Manual detailing the series of experiments needed to make relative RT-PCR data significant. For those researchers who have validated ß-actin as an appropriate internal control for their system, the QuantumRNA ß-actin Internal Standards are available.
The research team at Ambion has also generated over 50 Gene Specific Relative RT-PCR Kits. These kits contain primer pairs for specific human, mouse and rat genes, positive control DNA, a detailed Instruction Manual, and Ambion's exclusive QuantumRNA 18S rRNA primers and competimers. Kits are available for analysis of apoptosis genes, cytokines, cytokine receptors, growth factors, growth factor receptors and oncogenes.
Competitive RT-PCR
Competitive RT-PCR precisely quantitates a message by comparing RT-PCR product signal intensity to a concentration curve generated by a synthetic competitor RNA sequence. The competitor RNA transcript is designed for amplification by the same primers and with the same efficiency as the endogenous target. The competitor produces a different-sized product so that it can be distinguished from the endogenous target product by gel analysis. The competitor is carefully quantitated and titrated into replicate RNA samples. Pilot experiments are used to find the range of competitor concentration where the experimental signal is most similar. Finally, the mass of product in the experimental samples is compared to the curve to determine the amount of a specific RNA present in the sample.
Some protocols use DNA competitors or random sequences for competitive RT-PCR. These competitors do not effectively control for variations in the RT reaction or for the amplification efficiency of the specific experimental sequence, as do RNA competitors. See The Accuracy of Competitive RT-PCR Depends on Using the Right Exogenous Standard for a further discussion on competitor choice and design.
Ambion's RT-PCR Competitor Construction Kit (patent pending) provides transcription reagents for the synthesis of an RNA competitor that is RNase-resistant (Figure 2). RNase resistance is conferred by the incorporation of modified rNTP's into the competitor transcript. This makes the competitor highly resistant to RNase digestion which helps maintain its copy number even over extended storage. Long-term stability is important since enough competitor is synthesized in one reaction to perform thousands of experiments. Along with the reagents to transcribe an RNA competitor, the RT-PCR Competitor Construction Kit includes a detailed Instruction Manual describing the design, synthesis, quantitation, and storage of the RNA competitor sequence as well as protocols for competitive quantitative RT-PCR. 作者: 椰子叶子 时间: 2011-9-10 16:02
Figure 2. Nuclease Stability of RNA Synthesized with the RT-PCR Competitor Construction Kit. RNase A at the concentrations indicated was incubated at room temperature for one hour with radiolabeled standard RNA or RNA synthesized by the RT-PCR Competitor Construction Kit in 1X Transcription Buffer. The samples were assessed on 8% denaturing polyacrylamide gels and products were detected by autoradiography.
Comparative RT-PCR
While exquisitely sensitive, both relative and competitive methods of qRT-PCR have drawbacks. Relative RT-PCR requires extensive optimization to ensure that the PCR is terminated when both the gene of interest and an internal control are in the exponential phase of amplification. Competitive RT-PCR requires that an exogenous "competitor" be synthesized for each target to be analyzed. Ambion’s IntraSpec™ Comparative RT-PCR Kit (patent pending) achieves the same level of sensitivity as these standard methods of qRT-PCR, with significantly less optimization. Target mRNAs from 2 samples are assayed simultaneously, each serving as a competitor for the other, making it possible to compare the relative abundance of target between samples. Comparative RT-PCR is ideal for analyzing target genes discovered by screening methods such as array analysis and differential display. 作者: 小米虫子 时间: 2011-9-10 16:02
: NM_000610. Homo sapiens CD44...[gi:21361192] Links
LOCUS NM_000610 3091 bp mRNA linear PRI 07-MAR-2004
DEFINITION Homo sapiens CD44 antigen (homing function and Indian blood group
system) (CD44), mRNA.
ACCESSION NM_000610
VERSION NM_000610.2 GI:21361192
KEYWORDS .
SOURCE Homo sapiens (human)
LOCUS HSTCRAR 1508 bp mRNA linear PRI 29-JAN-1995
DEFINITION Human mRNA for T-cell receptor alpha chain (TCR-alpha).
ACCESSION X02592 M12959
VERSION X02592.1 GI:36944
KEYWORDS membrane protein; T-cell receptor; T-cell receptor alpha.
SOURCE Homo sapiens (human)
ORGANISM Homo sapiens
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
Mammalia; Eutheria; Primates; Catarrhini; Hominidae; Homo.
REFERENCE 1 (bases 1 to 1508)
AUTHORS Rabbitts,T.H., Lefranc,M.P., Stinson,M.A., Sims,J.E., Schroder,J.,
Steinmetz,M., Spurr,N.L., Solomon,E. and Goodfellow,P.N.
TITLE The chromosomal location of T-cell receptor genes and a T cell作者: 丸子妹 时间: 2011-9-13 17:25
rearranging gene: possible correlation with specific translocations
in human T cell leukaemia
JOURNAL EMBO J. 4 , 1461-1465 (1985)
MEDLINE 85284934
PUBMED 3875483
COMMENT On Jul 31, 2003 this sequence version replaced gi:338734.
FEATURES Location/Qualifiers
source 1..1508
/organism="Homo sapiens"
/mol_type="mRNA"
/strain="T-cell leukaemic cell line JM"
/db_xref="taxon:9606"
CDS 129..962
/codon_start=1
/product="TCR-alpha chain"
/protein_id="CAA26435.1"
/db_xref="GI:36945"
/db_xref="REMTREMBL:CAA26435"
/translation="MLLLLVPVLEVIFTLGGTRAQSVTQLGSHVSVSEGALVLLRCNY
SSSVPPYLFWYVQYPNQGLQLLLKYTSAATLVKGINGFEAEFKKSETSFHLTKPSAHM
SDAAEYFCAVSDLEPNSSASKIIFGSGTRLSIRPNIQNPDPAVYQLRDSKSSDKSVCL
FTDFDSQTNVSQSKDSDVYITDKTVLDMRSMDFKSNSAVAWSNKSDFACANAFNNSII
PEDTFFPSPESSCDVKLVEKSFETDTNLNFQNLSVIGFRILLLKVAGFNLLMTLRLWS
S"
misc_feature 468..485
/note="pot. variable region (aa 114-119)"
misc_feature 486..533
/note="pot. joining region (aa 120-135)"
misc_feature 534..959
/note="pot. constant region (aa 136-277)"
misc_feature 1492..1497
/note="pot. polyA signal"
ORIGIN 作者: 丸子妹 时间: 2011-9-13 17:29
Reference:
Altschul, Stephen F., Thomas L. Madden, Alejandro A. Schäffer,
Jinghui Zhang, Zheng Zhang, Webb Miller, and David J. Lipman (1997),
"Gapped BLAST and PSI-BLAST: a new generation of protein database search
programs", Nucleic Acids Res. 25:3389-3402.
RID: 1084088745-15152-180999400030.BLASTQ3
Query=
(54 letters)
Database: All GenBank+EMBL+DDBJ+PDB sequences (but no EST, STS,
GSS,environmental samples or phase 0, 1 or 2 HTGS sequences)
2,191,357 sequences; 10,作者: 浆果儿cc 时间: 2011-9-14 13:31
各位大虾:这是我将引物输入BLAST的检测结果,可我看不懂,请教教我!谢。
BLASTN 2.2.9 [May-01-2004]
Reference:
Altschul, Stephen F., Thomas L. Madden, Alejandro A. Schäffer,
Jinghui Zhang, Zheng Zhang, Webb Miller, and David J. Lipman (1997),
"Gapped BLAST and PSI-BLAST: a new generation of protein database search
programs", Nucleic Acids Res. 25:3389-3402.
RID: 1084088745-15152-180999400030.BLASTQ3
Query=
(54 letters)
Database: All GenBank+EMBL+DDBJ+PDB sequences (but no EST, STS,
GSS,environmental samples or phase 0, 1 or 2 HTGS sequences)
2,191,357 sequences; 10,537,999,113 total letters
If you have any problems or questions with the results of this search please refer to the BLAST FAQs
No significant similarity found. For reasons why, click here.
Lambda K H
1.37 0.711 1.31
Gapped
Lambda K H
1.37 0.711 1.31 作者: 浆果儿cc 时间: 2011-9-14 13:31
Gap Penalties: Existence: 5, Extension: 2
Number of Hits to DB: 401,494
Number of Sequences: 2191357
Number of extensions: 515
Number of successful extensions: 0
Number of sequences better than 10.0: 0
Number of HSP's better than 10.0 without gapping: 0
Number of HSP's successfully gapped in prelim test: 0
length of query: 54
length of database: 10,537,999,113
A: 0
X1: 11 (20.0 bits)
X2: 15 (30.0 bits)
X3: 25 (50.0 bits)
S1: 12 (25.0 bits) 作者: 浆果儿cc 时间: 2011-9-14 13:31
Gap Penalties: Existence: 5, Extension: 2
Number of Hits to DB: 401,494
Number of Sequences: 2191357
Number of extensions: 515
Number of successful extensions: 0
Number of sequences better than 10.0: 0
Number of HSP's better than 10.0 without gapping: 0
Number of HSP's successfully gapped in prelim test: 0
length of query: 54
length of database: 10,537,999,113
A: 0
X1: 11 (20.0 bits)
X2: 15 (30.0 bits)
X3: 25 (50.0 bits)
S1: 12 (25.0 bits) 作者: 椰子叶子 时间: 2011-9-14 13:32
我用了众多的反转录试剂盒中,觉得invitrogen的反转录试剂盒较好!“Superscript II Reverse Transcriptase" 非常好用!不过比较贵,你可以试试。 作者: 椰子叶子 时间: 2011-9-14 13:32
-T: 是HTML的简写,是指blast结果文件是否用HTML格式,默认是F!如果你想用IE
看,我建议用-T T
-e: 是Expectation value,期望值,默认是10,我用的10-10!
以上是简单的介绍,其实blastall的参数远远不止这些,有空在说了!
大家可以看看NCBI上的详细介绍,虽然是英文的!
Good luck for everyone!作者: 椰子叶子 时间: 2011-9-14 13:33
blastall 2.2.4 arguments:
-p Program Name [String]
-d Database [String]
default = nr
-i Query File [File In]
default = stdin
-e Expectation value (E) [Real]
default = 10.0
-m alignment view options:
0 = pairwise,
1 = query-anchored showing identities,
2 = query-anchored no identities,
3 = flat query-anchored, show identities,
4 = flat query-anchored, no identities,
5 = query-anchored no identities and blunt ends,
6 = flat query-anchored, no identities and blunt ends,
7 = XML Blast output,
8 = tabular,
9 tabular with comment lines [Integer]
default = 0
-o BLAST report Output File [File Out] Optional
default = stdout
-F Filter query sequence (DUST with blastn, SEG with others) [String]
default = T
-G Cost to open a gap (zero invokes default behavior) [Integer]
default = 0
-E Cost to extend a gap (zero invokes default behavior) [Integer]
default = 0作者: 椰子叶子 时间: 2011-9-14 13:34
-X X dropoff value for gapped alignment (in bits) (zero invokes
default behavior)
blastn 30, megablast 20, tblastx 0, all others 15 [Integer]
default = 0
-I Show GI's in deflines [T/F]
default = F
-q Penalty for a nucleotide mismatch (blastn only) [Integer]
default = -3
-r Reward for a nucleotide match (blastn only) [Integer]
default = 1
-v Number of database sequences to show one-line descriptions for (V)
[Integer]
default = 500
-b Number of database sequence to show alignments for ( [Integer]
default = 250
-f Threshold for extending hits, default if zero
blastp 11, blastn 0, blastx 12, tblastn 13
tblastx 13, megablast 0 [Integer]
default = 0
-g Perfom gapped alignment (not available with tblastx) [T/F]
default = T
-Q Query Genetic code to use [Integer]
default = 1
-D DB Genetic code (for tblast[nx] only) [Integer]
default = 1
-a Number of processors to use [Integer]
default = 1
-O SeqAlign file [File Out] Optional
-J Believe the query defline [T/F]
default = F
-M Matrix [String]
default = BLOSUM62
-W Word size, default if zero (blastn 11, megablast 28, all others 3)
[Integer]
default = 0作者: 椰子叶子 时间: 2011-9-14 13:34
-z Effective length of the database (use zero for the real size)
[Real]
default = 0
-K Number of best hits from a region to keep (off by default, if used
a value of 100 is recommended) [Integer]
default = 0
-Y Effective length of the search space (use zero for the real size)
[Real]
default = 0
-S Query strands to search against database (for blast[nx], and
tblastx)
3 is both, 1 is top, 2 is bottom [Integer]
default = 3
-T Produce HTML output [T/F]
default = F
-l Restrict search of database to list of GI's [String] Optional
-U Use lower case filtering of FASTA sequence [T/F] Optional
default = F
-y X dropoff value for ungapped extensions in bits (0.0 invokes
default behavior)
blastn 20, megablast 10, all others 7 [Real]
default = 0.0
-Z X dropoff value for final gapped alignment in bits (0.0 invokes
default behavior)
blastn/megablast 50, tblastx 0, all others 25 [Integer]
default = 0
-R PSI-TBLASTN checkpoint file [File In] Optional
-n MegaBlast search [T/F]
default = F作者: 椰子叶子 时间: 2011-9-14 13:34
-L Location on query sequence [String] Optional
-A Multiple Hits window size, default if zero (blastn/megablast 0, all
others 40 [Integer]
default = 0
-w Frame shift penalty (OOF algorithm for blastx) [Integer]
default = 0
-t Length of the largest intron allowed in tblastn for linking HSPs (0
disables linking) [Integer]
default = 0
Reference:
Altschul, Stephen F., Thomas L. Madden, Alejandro A. Schäffer,
Jinghui Zhang, Zheng Zhang, Webb Miller, and David J. Lipman (1997),
"Gapped BLAST and PSI-BLAST: a new generation of protein database search
programs", Nucleic Acids Res. 25:3389-3402.
RID: 1084155634-31562-113261863480.BLASTQ3
Query=
(21 letters)
Database: All GenBank+EMBL+DDBJ+PDB sequences (but no EST, STS,
GSS,environmental samples or phase 0, 1 or 2 HTGS sequences)
2,192,053 sequences; 10,542,095,270 total letters
If you have any problems or questions with the results of this search please refer to the BLAST FAQs
Taxonomy reports
Distribution of 37 Blast Hits on the Query Sequence
>gi|2358042|gb|AE000660.1|HUAE000660 Homo sapiens T-cell receptor alpha delta locus from bases 501613 to
752736 (section 3 of 5) of the Complete Nucleotide
Sequence
Length = 251124
Score = 42.1 bits (21), Expect = 0.007
Identities = 21/21 (100%)
Strand = Plus / Plus
Lambda K H
1.37 0.711 1.31 作者: 丸子妹 时间: 2011-9-14 13:41
Gapped
Lambda K H
1.37 0.711 1.31
Gap Penalties: Existence: 5, Extension: 2
Number of Hits to DB: 336,224
Number of Sequences: 2192053
Number of extensions: 2758
Number of successful extensions: 12
Number of sequences better than 10.0: 0
Number of HSP's better than 10.0 without gapping: 0
Number of HSP's successfully gapped in prelim test: 11
length of query: 21
length of database: 10,542,095,270
A: 0
X1: 11 (20.0 bits)
X2: 15 (30.0 bits)
X3: 25 (50.0 bits)
S1: 12 (25.0 bits) 作者: =菓子= 时间: 2011-9-14 13:42
Reference: ………………………………………………………………………(参考的文献)
Altschul, Stephen F., Thomas L. Madden, Alejandro A. Schäffer,
Jinghui Zhang, Zheng Zhang, Webb Miller, and David J. Lipman (1997),
"Gapped BLAST and PSI-BLAST: a new generation of protein database search
programs", Nucleic Acids Res. 25:3389-3402.
RID: 1084155634-31562-113261863480.BLASTQ3…………检索号
Query= (21 letters)…………………………………………查询为21的碱基
Database: All GenBank+EMBL+DDBJ+PDB sequences (but no EST, STS,
GSS,environmental samples or phase 0, 1 or 2 HTGS sequences)
2,192,053 sequences; 10,542,095,270 total letters………………数据库及特征
If you have any problems or questions with the results of this search please refer to the BLAST FAQs
Taxonomy reports
Distribution of 37 Blast Hits on the Query Sequence……分类报告,37个可以匹配的序列,下面一列为其详细列表,可以不理会
Score E
Sequences producing significant alignments: (bits) Value
gi|21363121|ref|NG_001332.1| Homo sapiens T cell receptor a... 42 0.007
Alignments
>gi|21363121|ref|NG_001332.1|
所匹配的序列号,点击可以链接得到
Homo sapiens T cell receptor alpha delta locus (TCRA/TCRD) on chromosome 14
所属基因为人类14号染色体TCR
Length = 1071646
长度1071646 Score = 42.1 bits (21), Expect = 0.007
Identities = 21/21 (100%)
Strand = Plus / Plus……………………………………21碱基100%匹配
Gap Penalties: Existence: 5, Extension: 2
Number of Hits to DB: 336,224
Number of Sequences: 2192053
Number of extensions: 2758
Number of successful extensions: 12
Number of sequences better than 10.0: 0
Number of HSP's better than 10.0 without gapping: 0
Number of HSP's successfully gapped in prelim test: 11
length of query: 21
length of database: 10,542,095,270
A: 0
X1: 11 (20.0 bits)
X2: 15 (30.0 bits)
X3: 25 (50.0 bits)
S1: 12 (25.0 bits)
请教!
我做SD大鼠肺组织的RT-PCR,需EGF引物,我在文献上查得下面几个:
sense primer 5-GTGGCGTGTGCATGTATGTT-3 (3357-3376)
antisense primer 5-CTCACGTTGCTGCTTGACTC-3 (3614-3633)
另外一个
forward primer 5-AGCAATTGGTGGTGGATG-3
reverse primer 5-ACTCTTTGCAAAAGTTGTC-3
鼠得全序列如下,如何验证?
LOCUS NM_012842 4801 bp mRNA linear ROD 24-DEC-2003
DEFINITION Rattus norvegicus epidermal growth factor (Egf), mRNA.
ACCESSION NM_012842
VERSION NM_012842.1 GI:6978796
KEYWORDS .
SOURCE Rattus norvegicus (Norway rat)
ORGANISM Rattus norvegicus
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
Mammalia; Eutheria; Rodentia; Sciurognathi; Muridae; Murinae;
Rattus.
REFERENCE 1 (bases 1 to 4801)
AUTHORS Kawamata,T., Yamaguchi,T., Shin-ya,K. and Hori,T.
TITLE Divergence in signaling pathways involved in promotion of cell
viability mediated by bFGF, NGF, and EGF in PC12 cells
JOURNAL Neurochem. Res. 28 , 1221-1225 (2003)
PUBMED 12834262
REMARK GeneRIF: role in divergence in signaling pathways involved in
promotion of cell viability
REFERENCE 2 (bases 1 to 4801)
AUTHORS Limesand,K.H., Barzen,K.A., Quissell,D.O. and Anderson,S.M.
TITLE Synergistic suppression of apoptosis in salivary acinar cells by
IGF1 and EGF
JOURNAL Cell Death Differ. 10 (3), 345-355 (2003)
PUBMED 12700634作者: 丸子妹 时间: 2011-9-14 16:11
REMARK GeneRIF: IGF1 and EGF synergistically suppress apoptosis in
salivary acinar cells
REFERENCE 3 (bases 1 to 4801)
AUTHORS Martinez,R. and Gomes,F.C.
TITLE Neuritogenesis induced by thyroid hormone-treated astrocytes is
mediated by epidermal growth factor/mitogen-activated protein
kinase-phosphatidylinositol 3-kinase pathways and involves
modulation of extracellular matrix proteins
JOURNAL J. Biol. Chem. 277 (51), 49311-49318 (2002)
PUBMED 12356760
REMARK GeneRIF: EGF plays a role in T3-induced cerebellar development in
astrocytes
REFERENCE 4 (bases 1 to 4801)
AUTHORS Pickett,C.A., Manning,N., Akita,Y. and Gutierrez-Hartmann,A.
TITLE Role of specific protein kinase C isozymes in mediating epidermal
growth factor, thyrotropin-releasing hormone, and phorbol ester
regulation of the rat prolactin promoter in GH4/GH4C1 pituitary
cells
JOURNAL Mol. Endocrinol. 16 (12), 2840-2852 (2002)
PUBMED 12456804
REMARK GeneRIF: both epidermal growth factor and thyrotropin releasing
hormone stimulated prolactin gene transcription appear to require
protein kinase C delta, whereas protein kinase C eta may also be
able to transmit the epidermal growth factor response
REFERENCE 5 (bases 1 to 4801)
AUTHORS Hallak,H., Moehren,G., Tang,J., Kaou,M., Addas,M., Hoek,J.B. and
Rubin,R.
TITLE Epidermal growth factor-induced activation of the insulin-like
growth factor I receptor in rat hepatocytes
JOURNAL Hepatology 36 , 1509-1518 (2002)
PUBMED 12447877
REMARK GeneRIF: EGF- and Src-mediated transactivation pathway for IGF-IR
activation in hepatocytes, and indicate a role for the IGF-IR in
hepatocyte intracellular signaling.
REFERENCE 6 (bases 1 to 4801)作者: 丸子妹 时间: 2011-9-14 16:11
AUTHORS Fukamachi,K., Matsuoka,Y., Ohno,H., Hamaguchi,T. and Tsuda,H.
TITLE Neuronal leucine-rich repeat protein-3 amplifies MAPK activation by
epidermal growth factor through a carboxyl-terminal region
containing endocytosis motifs
JOURNAL J. Biol. Chem. 277 (46), 43549-43552 (2002)
PUBMED 12297494
REMARK GeneRIF: EGF is internalized into clathrin-coated vesicles by
NLRR-3, resulting in Ras-MAPK signaling
REFERENCE 7 (bases 1 to 4801)
AUTHORS LeBedis,C., Chen,K., Fallavollita,L., Boutros,T. and Brodt,P.
TITLE Peripheral lymph node stromal cells can promote growth and
tumorigenicity of breast carcinoma cells through the release of
IGF-I and EGF
JOURNAL Int. J. Cancer 100 (1), 2-8 (2002)
PUBMED 12115579
REMARK GeneRIF: lymph node stromal cell lines expressed mRNA transcripts
for IGF-I and EGF as major mitogenic factors which may contribute
actively to the process of cancer cell dissemination
REFERENCE 8 (bases 1 to 4801)
AUTHORS Thulesen,J., Bor,M.V., Thulesen,S., Nexo,E., Poulsen,S.S. and
Jorgensen,P.E.
TITLE Altered secretion and processing of epidermal growth factor in
adrenergic-induced growth of the rat submandibular gland
JOURNAL Regul. Pept. 106 (1-3), 105-114 (2002)
PUBMED 12047917
REMARK GeneRIF: isoproterenol treatment leads to a hyperstimulatory state
of granular convoluted tubule cells, which then causes depletion of
cellular stores of mature EGF, and most likely due to a shortened
posttranslational transit, incomplete peptide processing
REFERENCE 9 (bases 1 to 4801)
AUTHORS DiCamillo,S.J., Carreras,I., Panchenko,M.V., Stone,P.J.,
Nugent,M.A., Foster,J.A. and Panchenko,M.P.
TITLE Elastase-released epidermal growth factor recruits epidermal growth
factor receptor and extracellular signal-regulated kinases to
down-regulate tropoelastin mRNA in lung fibroblasts
JOURNAL J. Biol. Chem. 277 (21), 18938-18946 (2002)
PUBMED 11889128
REMARK GeneRIF: stimulation of recruits epidermal growth factor receptor
and extracellular signal-regulated kinases to down-regulate
tropoelastin mRNA in lung fibroblasts
REFERENCE 10 (bases 1 to 4801)
AUTHORS Yang,L.T., Alexandropoulos,K. and Sap,J.
TITLE c-SRC mediates neurite outgrowth through recruitment of Crk to the
scaffolding protein Sin/Efs without altering the kinetics of ERK
activation
JOURNAL J. Biol. Chem. 277 (20), 17406-17414 (2002)
PUBMED 11867627作者: 丸子妹 时间: 2011-9-14 16:12
REMARK GeneRIF: epidermal growth factor (EGF) can be converted from a
non-neuritogenic into a neuritogenic factor through moderate
activation of endogenous SRC by receptor-protein-tyrosine
phosphatase alpha (a physiological SRC activator)
REFERENCE 11 (bases 1 to 4801)
AUTHORS Saggi,S.J., Safirstein,R. and Price,P.M.
TITLE Cloning and sequencing of the rat preproepidermal growth factor
cDNA: comparison with mouse and human sequences
JOURNAL DNA Cell Biol. 11 , 481-487 (1992)
PUBMED 1524680
COMMENT PROVISIONAL REFSEQ: This record has not yet been subject to final
NCBI review. The reference sequence was derived from U04842.1.
FEATURES Location/Qualifiers
source 1..4801
/organism="Rattus norvegicus"
/mol_type="mRNA"
/db_xref="taxon:10116"
/chromosome="2"
/map="2q42-q43"
gene 1..4801
/gene="Egf"
/db_xref="GeneID:25313"
/db_xref="LocusID:25313"
/db_xref="RATMAP:41197"
/db_xref="RGD:2542"
CDS 389..3790
/gene="Egf"
/note="go_component: membrane fraction [goid 0005624]
[evidence IEA];
go_component: membrane [goid 0016020] [evidence IEA];
go_component: integral to membrane [goid 0016021]
[evidence IEA];
go_component: extracellular space [goid 0005615] [evidence
IEA];
go_function: calcium ion binding [goid 0005509] [evidence
IEA];作者: 丸子妹 时间: 2011-9-14 16:12
请教!
我做SD大鼠肺组织的RT-PCR,需EGF引物,我在文献上查得下面几个:
sense primer 5-GTGGCGTGTGCATGTATGTT-3 (3357-3376)
antisense primer 5-CTCACGTTGCTGCTTGACTC-3 (3614-3633)
另外一个
forward primer 5-AGCAATTGGTGGTGGATG-3
reverse primer 5-ACTCTTTGCAAAAGTTGTC-3
鼠得全序列如下,如何验证?
LOCUS NM_012842 4801 bp mRNA linear ROD 24-DEC-2003
DEFINITION Rattus norvegicus epidermal growth factor (Egf), mRNA.
ACCESSION NM_012842
VERSION NM_012842.1 GI:6978796
KEYWORDS .
SOURCE Rattus norvegicus (Norway rat)
ORGANISM Rattus norvegicus
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
Mammalia; Eutheria; Rodentia; Sciurognathi; Muridae; Murinae;
Rattus.
REFERENCE 1 (bases 1 to 4801)
AUTHORS Kawamata,T., Yamaguchi,T., Shin-ya,K. and Hori,T.
TITLE Divergence in signaling pathways involved in promotion of cell
viability mediated by bFGF, NGF, and EGF in PC12 cells
JOURNAL Neurochem. Res. 28 , 1221-1225 (2003)
PUBMED 12834262
REMARK GeneRIF: role in divergence in signaling pathways involved in
promotion of cell viability
REFERENCE 2 (bases 1 to 4801)
AUTHORS Limesand,K.H., Barzen,K.A., Quissell,D.O. and Anderson,S.M.
......
那位高手帮忙设计一下引物:人B7-H1基因,谢谢!!!
LOCUS NM_014143 1553 bp mRNA linear PRI 21-DEC-2003
DEFINITION Homo sapiens programmed cell death 1 ligand 1 (PDCD1LG1), mRNA.
ACCESSION NM_014143
VERSION NM_014143.2 GI:20070268
KEYWORDS .
SOURCE Homo sapiens (human)
ORGANISM Homo sapiens
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
Mammalia; Eutheria; Primates; Catarrhini; Hominidae; Homo.
REFERENCE 1 (bases 1 to 1553)
AUTHORS Wiendl,H., Mitsdoerffer,M., Schneider,D., Chen,L., Lochmuller,H.,
Melms,A. and Weller,M.
TITLE Human muscle cells express a B7-related molecule, B7-H1, with
strong negative immune作者: jude 时间: 2011-9-14 17:06
那位高手帮忙设计一下引物:人B7-H1基因,谢谢!!!
LOCUS NM_014143 1553 bp mRNA linear PRI 21-DEC-2003
DEFINITION Homo sapiens programmed cell death 1 ligand 1 (PDCD1LG1), mRNA.
ACCESSION NM_014143
VERSION NM_014143.2 GI:20070268
KEYWORDS .
SOURCE Homo sapiens (human)
ORGANISM Homo sapiens
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
Mammalia; Eutheria; Primates; Catarrhini; Hominidae; Homo.
REFERENCE 1 (bases 1 to 1553)
AUTHORS Wiendl,H., Mitsdoerffer,M., Schneider,D., Chen,L., Lochmuller,H.,
Melms,A. and Weller,M.
TITLE Human muscle cells express a B7-related molecule, B7-H1, with
strong negative immune regulatory potential: a novel mechanism of
counterbalancing the immune attack in idiopathic inflammatory
myopathies
JOURNAL FASEB J. 17 (13), 1892-1894 (2003)
PUBMED 12923066
REMARK GeneRIF: B7-H1 is expressed in muscle cells and may have a negative
immune regulatory function in idiopathic inflammatory myopathies.
REFERENCE 2 (bases 1 to 1553)
AUTHORS Youngnak,P., Kozono,Y., Kozono,H., Iwai,H., Otsuki,N., Jin,H.,
Omura,K., Yagita,H., Pardoll,D.M., Chen,L. and Azuma,M.
TITLE Differential binding properties of B7-H1 and B7-DC to programmed
death-1
JOURNAL Biochem. Biophys. Res. Commun. 307 (3), 672-677 (2003)
PUBMED 12893276
REMARK GeneRIF: binding properties of B7-H1 to programmed death-1.
REFERENCE 3 (bases 1 to 1553)
AUTHORS Chen,X.L., Cao,X.D., Kang,A.J., Wang,K.M., Su,B.S. and Wang,Y.L.
TITLE In situ expression and significance of B7 costimulatory molecules
within tissues of human gastric carcinoma
JOURNAL World J. Gastroenterol. 9 , 1370-1373 (2003)作者: jude 时间: 2011-9-14 17:07
PUBMED 12800259
REMARK GeneRIF: ICOS-B7H costimulatory pathway may be involved in the
negative regulation of cell-mediated immune responses.
REFERENCE 4 (bases 1 to 1553)
AUTHORS Selenko-Gebauer,N., Majdic,O., Szekeres,A., Hofler,G., Guthann,E.,
Korthauer,U., Zlabinger,G., Steinberger,P., Pickl,W.F.,
Stockinger,H., Knapp,W. and Stockl,J.
TITLE B7-H1 (programmed death-1 ligand) on dendritic cells is involved in
the induction and maintenance of T cell anergy
JOURNAL J. Immunol. 170 (7), 3637-3644 (2003)
PUBMED 12646628
REMARK GeneRIF: Monoclonal antibody DF272-defined surface molecule B7-H1
represents a unique receptor structure on dendritic cells that may
play a role in the induction and maintenance of T cell anergy.
REFERENCE 5 (bases 1 to 1553)
AUTHORS Trabattoni,D., Saresella,M., Biasin,M., Boasso,A., Piacentini,L.,
Ferrante,P., Dong,H., Maserati,R., Shearer,G.M., Chen,L. and
Clerici,M.
TITLE B7-H1 is up-regulated in HIV infection and is a novel surrogate
marker of disease progression
JOURNAL Blood 101 (7), 2514-2520 (2003)
PUBMED 12468426
REMARK GeneRIF: up-regulation in HIV infection, relation to disease
progression, and possible role in AIDS progression
REFERENCE 6 (bases 1 to 1553)
AUTHORS Brown,J.A., Dorfman,D.M., Ma,F.R., Sullivan,E.L., Munoz,O.,
Wood,C.R., Greenfield,E.A. and Freeman,G.J.
TITLE Blockade of programmed death-1 ligands on dendritic cells enhances
T cell activation and cytokine production
JOURNAL J. Immunol. 170 (3), 1257-1266 (2003)
PUBMED 12538684
REMARK GeneRIF: Blockade of PD-L1 during T cell responses initiated by
allogenic dendritic cells increases T cell proliferation and
cytokine production, showing that PD-L1 functions to inhibit T cell
activation.作者: jude 时间: 2011-9-14 17:08
REFERENCE 7 (bases 1 to 1553)
AUTHORS Mazanet,M.M. and Hughes,C.C.
TITLE B7-H1 is expressed by human endothelial cells and suppresses T cell
cytokine synthesis
JOURNAL J. Immunol. 169 (7), 3581-3588 (2002)
PUBMED 12244148
REMARK GeneRIF: B7-H1 is inducible on human endothelial cells by IFN-gamma
both in vitro and in vivo; blocking its interaction with its
receptor (PD-1) on T cells augments T cell cytokine synthesis.
REFERENCE 8 (bases 1 to 1553)
AUTHORS Dong,H., Strome,S.E., Salomao,D.R., Tamura,H., Hirano,F.,
Flies,D.B., Roche,P.C., Lu,J., Zhu,G., Tamada,K., Lennon,V.A.,
Celis,E. and Chen,L.
TITLE Tumor-associated B7-H1 promotes T-cell apoptosis: a potential
mechanism of immune evasion
JOURNAL Nat. Med. 8 , 793-800 (2002)
PUBMED 12091876
REMARK GeneRIF: Cancer cell-associated B7-H1 increases apoptosis of
antigen-specific human T-cell clones in vitro
REFERENCE 9 (bases 1 to 1553)
AUTHORS Freeman,G.J., Long,A.J., Iwai,Y., Bourque,K., Chernova,T.,
Nishimura,H., Fitz,L.J., Malenkovich,N., Okazaki,T., Byrne,M.C.,
Horton,H.F., Fouser,L., Carter,L., Ling,V., Bowman,M.R.,
Carreno,B.M., Collins,M., Wood,C.R. and Honjo,T.
TITLE Engagement of the PD-1 immunoinhibitory receptor by a novel B7
family member leads to negative regulation of lymphocyte activation
JOURNAL J. Exp. Med. 192 (7), 1027-1034 (2000)
PUBMED 11015443
REFERENCE 10 (bases 1 to 1553)
AUTHORS Dong,H., Zhu,G., Tamada,K. and Chen,L.
TITLE B7-H1, a third member of the B7 family, co-stimulates T-cell
proliferation and interleukin-10 secretion
JOURNAL Nat. Med. 5 (12), 1365-1369 (1999)
PUBMED 10581077
COMMENT PROVISIONAL REFSEQ: This record has not yet been subject to final
NCBI review. The reference sequence was derived from AF233516.1.
On Apr 8, 2002 this sequence version replaced gi:7661533.
FEATURES Location/Qualifiers
source 1..1553
/organism="Homo sapiens"
/mol_type="mRNA"
/db_xref="taxon:9606"
/chromosome="9"
/map="9p24"
gene 1..1553
/gene="PDCD1LG1"
/note="synonyms: B7-H, B7H1, PDL1, PD-L1, PDCD1L1"
/db_xref="GeneID:29126"
/db_xref="LocusID:29126"
/db_xref="MIM:605402"
CDS 53..925作者: jude 时间: 2011-9-14 17:09