抛砖引玉,这是我以前发的老贴: 植物蛋白质提取的三种protocols 1. TCA/丙酮法: (1)取4g果肉,用液氮在研钵中将其研磨成粉。 (2)加入12.5%冰冷的TCA/丙酮(含0.07%β-巯基乙醇),匀浆液在-20 ºC下放置3h,纱布过滤。 (3)滤液在20000g离心30min,收集沉淀。 (4)用冷丙酮洗3次,沉淀在4ºC下干燥,备用。 2. 匀浆法: (1)称取4g果肉,用液氮在研钵中研磨成粉。 (2)加入4ml的匀浆缓冲液(匀浆液中含有20 mM Tris-HCl (pH 7.5), 250 mM sucrose, 10 mM EGTA, 1 mM PMSF, 1 mM DTT, 以及1% Triton X-100),继续研磨。 (3)匀浆液20000g离心30min。 (4)将上清转移到新的离心管中,加入终浓度为10%TCA溶液,4ºC下放置2 h。 (5)20000g离心40min,收集沉淀。 (6)用冷丙酮洗3次,沉淀在4ºC下干燥,备用。 3. 酚提取法: (1)称取4g果肉,用液氮在研钵中研磨成粉。 (2)加入4ml的匀浆缓冲液(匀浆液中含有20 mM Tris-HCl (pH 7.5), 250 mM sucrose, 10 mM EGTA, 1 mM PMSF, 1 mM DTT, 以及1% Triton X-100),继续研磨。 (3)匀浆液20000g离心30min。 (4)在上清液中加入等体积的pH7.8 Tris-饱和酚,充分摇荡,混匀,10000g,4ºC下离心30min,上层为水相,中间白色物质为杂质,下层为酚相。(注:当提高匀浆缓冲液中sucrose的浓度到1M时,酚相会出现在上层。) (5)回收酚相,加入5倍体积含0.1M 乙酸铵的预冷甲醇,充分混匀,-20ºC下过夜,沉淀蛋白。 (6)沉淀用含0.1M 乙酸铵的预冷甲醇洗2次。预冷丙酮洗2次。 (7)沉淀在4ºC下干燥,备用。 参考文献: Saravanan R S, Rose J K C. 2004. A critical evaluation of sample extraction techniques for enhanced proteomic analysis of recalcitrant plant tissues. Proteomics, 4: 2522-2532. Shen S H, Jing Y X, Kuang T Y. 2003a. Proteomics approach to identify wound-response related proteins from rice leaf sheath. Proteomics, 3: 527-535. Shen S H, Sharma A, Komatsu S. 2003b. Characterization of proteins responsive to Gibberellin in the leaf-sheath of rice Oryza sativa L seedling using proteome analysis. Biol Pharm Bull, 26: 129-136. Chan, Z.L., Qin, G.Z., Xu, X.B., Li, B.Q., and Tian, S.P. 2007. Proteome approach to characterize proteins induced by antagonist yeast and salicylic acid in peach fruit. J. Proteome Res. 6: 1677-1688作者: xingyi08 时间: 2012-12-3 14:28
贴东西,顺便让czlong2008修改 2.2 Preparation of total protein extract For protein extraction about 1 g(1 part) of this fine powder was mixed with 5 ml(5 parts) of precipitation solution containing 10% w/v TCA and 0.07% w/v β-mercaptoethanol in cold acetone which was stored at –20°C overnight according to Isaacson et al(2006). Aliquots of suspension were incubated at –20°C for 60 min. After 5, 15, and 30 min the suspension was mixed, and most proteins will precipitate with in 30 min. Precipitated material was collected by centrifugation(18 000 g, 4°C, 15 min), proteins should precipitate as white flakes. After washing twice with acetone containing 0.07% w/v β-mercaptoethanol the precipitates were dried in a cold vacuum centrifuge. The pellets were resuspended using 25 μL lysis buffer(5 M urea, 2 M thiourea, 2% CHAPS, 2% SB3-10, 40 mM Tris, 65 mM DTT and 0.35% carrier amholytes) per milligramme(Wang et al. 2007), extensively vortexed at room temperature, and then centrifuged at 21 000 g for 10 min at 28°C. Protein concentration was determined by the Bradford assay(Ramagli 1999).作者: moonlight45 时间: 2012-12-3 14:32
Lysis Buffer 7M Urea 2M Thiourea 4% CHAPS Add fresh: 20mM Spermine 20mM DTT 1mM PMSF Rehydration Buffer 8M Urea 2% CHAPS Add fresh: 20mM DTT 0.5% IPG Buffer trace amount of bromophenol blue Equilibration Buffer 6M Urea 30% Glycerol 2% SDS 50mM Tris-HCl pH 8.8 EQ Buffer 1 – add fresh 1% DTT EQ Buffer 2 – add fresh 2.5% Iodoacetamide Sample Preparation 1) Remove media from flasks. 2) Add 4mL of trypsin to each flask and place back in incubator for 2-3 minutes. 3) Remove flasks from incubator and add 4mL of media to each flask to inactivate trypsin. 4) Collect cells into 15mL conical tubes and spin @ 3K RPM for 5-10 minutes at RT. 5) Remove supernatant from conical tubes and add 5mL of 1X PBS to each tube. 6) Resuspend cells in 1X PBS in order to remove excess trypsin and media. 7) Spin @ 3K RPM for 5-10 minutes at RT. 8) Remove supernatant from conical tubes and add 1mL of fresh lysis buffer to each tube. 9) Resuspend cells in fresh lysis buffer then place tubes in refrigerator at 4°C for 2-4 hours. 10) Transfer cell lysates into 1.5mL microcentrifuge tubes (Beckman tubes) and spin at 40K RPM for 1 hour at 4°C. 11) Carefully remove supernatant and transfer to clean microcentrifuge tube. 12) Determine protein concentration and store remaining lysate in -80°C freezer. Isoelectric Focusing/The First Dimension 1) Prepare 2.5mL of fresh rehydration buffer for each type of DryStrip. 2) Place samples on ice to thaw and collect 1.5mL microcentrifuge tubes for sample dilution. 3) Remove the necessary number of DryStrips from -20°C freezer. 4) Determine the amount of rehydration buffer necessary for strip length. 5) Add 200-300ug of cell lysate to clean microcentrifuge tubes and add the difference between the total volume and the volume of sample using fresh rehydration buffer. 6) Remove plastic cover from strip holder and set aside. 7) Add rehydration buffer containing sample to the strip holder at the anode (pointed end of the holder). 8) Remove protective cover from DryStrip before placing gel side down into strip holder starting at the anode (pointed end) and laying strip down to the cathode (blunt end). 9) Move strip back and forth in order to spread out rehydration buffer. 10) Make sure that all bubbles are removed from underneath the DryStrip before adding DryStrip Cover Fluid (Mineral Oil). 11) Add cover fluid from one end until it reaches the middle of the strip holder then add from the opposite side so that fluid meets in the middle. 12) Complete the same process for all strips then place the strip holders on IPGphor system. 13) Set up protocol for the length strip that is being used. 14) For 13cm strip: Rehydration at 20°C for 12 hours 50uA per strip 500V for 1 hour 1000V for 1 hour 8000V for 3-5 hours 15) Move onto equilibration step or rinse strip with MilliQ water and place into screw cap tubes for storing in -70°C freezer. Equilibration 1) Prepare 15 mL of fresh equilibration buffers 1 & 2 for each strip. 2) Wash strips with MilliQ water before placing into equilibration buffer 1. If you are removing strip from -70°C, let tube sit on lab bench to thaw strip. When strip is thawed (strip will be clear) place into equilibration buffer 1. 3) Incubate in equilibration buffer 1 for 15 minutes. 4) Remove strip and rinse with MilliQ water before placing into equilibration buffer 2. 5) Incubate in equilibration buffer 2 for 15 minutes. 6) Remove strip and rinse with MilliQ water and place strip on its side on filter paper to allow excess water to drain from strip. Running the Second Dimension 1) Prepare gel by removing water saturated butanol from top of gel and washing with 1X running 作者: huifeng0516 时间: 2012-12-3 14:34
buffer. 2) Cover top of gel with 1X running buffer and lay strip across the top of the gel making sure that the gel is lying flush with the gel and remove any bubbles between the strip and the top of the gel. 3) Remove the running buffer and add warm 1% agarose made with 1X running buffer. 4) Allow the agarose to cool and solidify, which should only take a few minutes, before moving to the electrophoresis apparatus. 5) Add 1X running buffer to the upper and lower buffer chambers and place gel inside apparatus. 6) Run gel for 15 minutes at 10mA per gel then run gel at 25mA per gel for 4-6 hours (until BPB band reaches bottom of gel). 7) Remove gel from plates and stain. 1-D Polyacrylamide Gel Electrophoresis Gel type Sample volume(μl/well) Total well volume(μl/well) Mini Gels 0.75 mm, 10 well 2 to 5 25 Large Gels 0.75 mm, 10 wells 10-140 150 Sample buffer 0.062 M tris-HCl, pH6.8 2% SDS 0.01% Bromophenol Blue 10% Glycerol 5% 2-mercaptoethanol Upper buffer 10% SDS 10 mL 250mM EDTA 4 mL Reservoir buffer 100 mL Nanopure water add enough to 1 L mark Lower buffer Reservoir buffer 100 ml Nanopure water add enough to 1 L mark Store buffers in refrigerator. Sample Preparation 1. Prepare the sample with the sample buffer to a concentration of 1 μg/μl. 2. Heat at 100 °C for 2-3 min in a boiling water bath. Sample loading 1. Remove the comb from the cassette by sliding it slowly with a steady motion straight up. Do not distort or tear any wells. 2. Flush the wells with water to remove residual acrylamide 3. For glass cassettes leave the tape on the side of the gels. 4. Use permanent marker to draw the bottoms of the wells. That will make it easier to load. 5. Insert these plates on the electrophoresis unit. 6. Pour the upper and the lower buffers 7. Load the appropriate amounts of samples. Load sample buffer in any wells that do not contain samples. Gel Visualization Copper Staining 1. Prepare the Copper stain by dissolving 4 g of CuCl2 in 100 mL of water. 2. Wash the gels with nanopure water. 3. Pour the Cu stain on the gel. Make sure that the gel is completely submerged. 4. Rock for 5 minutes. 5. Pour the stain into the waste and wash the gel with water to remove excess copper. 6. Store the gel in water in the refrigerator. Zn Staining 1. Dilute Imidazole (Solution A) 1:10 with water, mix thoroughly. Dilute Zinc Sulfate (Solution B) 1:10 with deionized water, mix thoroughly. Gels will require 100-150 mL so that they are compeletely immersed. 2. Place the gel in a staining container and add Imidazole, solution A. Rock at room temperature for 10 min. 3. Decant Solution A, and add the dilute Zinc sulfate, solution B. Make sure the gel is completely covered to ensure even staining. Rock at room temperature for 30 sec approx while the gel develops. 4. Decant solution B, and add 100 mL of water. Rinse for 3-5 min rocking at room temperature 5. Decant water and replace with fresh water. The gel can be stored like this for days. Silver Staining for Mass Spectrometric Analysis Step Solution per gel Time(min) Fix 25 ml acetic acid, 100ml methanol, 125 ml water 15 Fix 25 ml acetic acid, 100 ml methanol, 125 ml water 15 Sensitization 75 ml methanol, 10 ml sodium thiosulfate(5%), 17 g sodium acetate, 165 water 30 Wash 250 ml water 5 Wash 250 ml water 5 Wash 250 ml water 5 Silver 25 ml silver nitrate(2.5%), 225 water 20 Wash 250 ml water 1 Wash 250 ml water 1 Develop 6.25 g sodium carbonate, 100 ul formaldehyde 250 ml water Stop 3.65 g EDTA 250 water 10 Wash 250 ml Water 5 Wash 250 ml Water 5 Wash 250 ml Water 5 Destaining Silver from the gels WORKING SOLUTION 30 mM Potassium Ferricyanide 99 mg of Potassium Ferricyanide in 10 ml water 100 mM Sodium Thiosulfate 248 mg Sodium Thiosulfate in 10 ml water Mix them together. Make fresh for use. Add 30-50uL working solution to cover the gel bands and vortex 作者: huifeng0516 时间: 2012-12-3 14:35
occasionally. Repeat till there is no more brown color left. Rinse with water , twice. Cover the gel with 200mM ammonium bicarbonate for 20 min. Discard the liquid to waste. Wash with ACN till the gel pieces are opaque. Dry the pieces under vacuum for 30 min Alternative Version: Silver Staining for Mass Spectrometric Analysis (Use 5 gel volumes of each reagent for staining) Step Solution per gel Time(min) Fix 5% acetic acid; 45% methanol; 50% water 90 Wash water 10 Wash water 10 Sensitization 0.02% sodium thiosulfate 3 Wash water 0.5 Wash water 0.5 Silver 0.1% silver nitrate 30 Wash water 0.5 Develop 0.02% formaldehyde/2.5% sodium carbonate 2 (bands suitable for MS analysis will appear within 30-60 seconds) Stop 1% acetic acid 10 Wash water 20 Wash water 20 Alternate Version: Destaining Silver from the gels WORKING SOLUTION 30 mM Potassium Ferricyanide 99 mg of Potassium Ferricyanide in 10 ml water 100 mM Sodium Thiosulfate 248 mg Sodium Thiosulfate in 10 ml water Mix at 1:1 ratio. Make fresh for use. Cover the band in working solution and vortex until brown color removed (5 minutes) Remove the solution and wash three times with 200 μL water. In-gel Digestion 100 mM Ammonium Bicarbonate 0.79 g Ammonium Bicarbonate Make up to 100 mL with water 10 mM DTT 15.4 mg Dithiothreitol Make up to 10 mL with 100 mM ammonium bicarbonate 55 mM Iodoacetamide 102 mg Iodoacetamide Make up to 10 ml with 100 mM ammonium bicarbonate 0.1 μg/μl Trypsin 200 μl of 25 mM Ammonium Bicarbonate 20 μg trypsin Excise gel bands prior to in-gel digestion作者: lxh031 时间: 2012-12-3 14:35
Total protein was isolated from fully expanded mature leaves based upon a two-step procedure combining TCA/acetone precipitation and phenol extraction according to Wang et al. (2003), with some modification: (ⅰ) preparation of dry plant tissue power. Frozen leaf material (about 1 g) was pulverized to a fine powder in liquid nitrogen using a mortar and pestle, and then the powder was resuspended in a solution of 10% trichloroacetic acid (TCA) in acetone containing 0.07% 2-mercaptoethanol (2-ME). Proteins were allowed to precipitate for 1 h at −20°C, followed by centrifugation at 15000 g for 15 min at 4°C. The resultant pellet was sequentially rinsed with 10% TCA in acetone containing 0.07% 2-ME several times until the pellet was colorless, and then washed twice with cold acetone twice, and finally twice with cold 80% acetone. Each time the pellet was resuspended completely by vortexing and then centrifuged as above. The final pellet was dried under vacuum and used for phenol extraction of proteins or stored at -80°C for further use. (ⅱ)protein extraction. Phenol extraction of proteins is based on the protocol described by Hurkman and Tanaka (1986). The dried tissue powder was completely resuspended in 5 mL of extraction buffer (0.7 M sucrose, 0.5 M Tris-HCl, pH 7.5, 50 mM EDTA, 0.1 M KCl, 1% w/v polyvinylpyrrolidone (PVP), 2% v/v 2-mercaptoethanol, and 2 mM PMSF), by vortexing thoroughly for 30 min at 4°C. An equal volume of Tris-HCl saturated phenol pH 7.8 was added to the protein suspension. After an additional 30 min of shaking at 4°C, the phases were separated by centrifugation (16000 g for 30 min at 4°C). The phenol phase was collected and re-extracted with an equal volume of extraction buffer. Proteins were precipitated from the phenol phase by adding 5 volumes of 0.1 M ammonium acetate in methanol and incubated at least 2 h or overnight at -20°C. After centrifuging at 16 000g for 15 min (4°C), the collected protein pellets were washed three times with cold 0.1 M ammonium acetate in methanol, and then washed twice with cold 80% acetone. The final protein pellet was dried under vacuum at 4°C and resuspended in 500 μL of solubilization buffer (7 M urea, 2 M thiourea, 0.4% v/v Triton X-100, 4% w/v CHAPS, 1% dithiothreitol (DTT), 1% v/v IPG buffer pH 4–7) by incubating at room temperature for 1 h. Insoluble matter was removed by centrifugation for 20 min at 16,000g. Protein concentration was determined using Bradford assay (1976).作者: xue258 时间: 2012-12-3 14:38
Powdered fruit or peel tissue (0.2 g) was placed in a 2.0 mL microfuge tube and the protein precipitated at 2207C for 45 min with 1.75 mL of a precipitation solution (10%TCA in ice-cold acetone). The precipitated protein was centrifuged for 10 min at 10 0006g at 297C. The supernatant was discarded and the pellet rinsed with 2 mL of ice-cold acetone and stored at 2207C for 1 h to remove residual TCA then further centrifuged for 15 min at 10 0006g at 2207C. Acetone rinses were repeated until a white pellet was obtained. The protein pellet was dried under vacuum for 5 min and then dissolved in varying volumes of buffer containing 5 M urea, 2 M thiourea, 2%CHAPS, 2% N-decyl-N,N-dimethyl-3- ammonio-1-propanesulfonate, 20 mM DTT, 5 mM tris(2- carboxyethyl) phosphine hydrochloride, and two carrier ampholytes 0.5%pH 4–6.5 and 0.25%pH 3–11 nonlinear.作者: pengke1983 时间: 2012-12-3 15:20
蛋白质分析技术(Western Blot、ELISA、免疫荧光与免疫组化技术) 1 原理: 将通过聚丙烯酰胺凝胶电泳分离的蛋白质转移到硝酸纤维素或PVDF膜上,然后与能特异性识别待检蛋白的抗体进行反应,洗涤去除没有结合的特异性抗体后,加入标记的、能识别特异性抗体的种属特异性抗体,反应一段时间后再次洗涤去除非特异性结合的标记抗体,加入适合标记物的检测试剂进行显色或发光等,观察有无特异性蛋白条带的出现,也可通过条带的密度大小来进行特异性蛋白的半定量。 2 操作过程 SDS-PAGE电泳→转膜(PVDF或硝酸纤维素膜) 封闭→一抗→洗涤→酶标二抗反应 洗涤→显色或化学发光显影 Western blot analysis of the cleavage of Caspase-3. IM9/Bcl-2 Cells were treated with 20mM of gossypol for 4, 8 and 16 h. After treatment, cells were harvested and lysed in lysis buffer. 50ug of protein was loaded in each lane and the expression of actin was detected as a loading control. Cytochrome c release from mitochondria to cytosol in gossypol-treated IM-9/Bcl-2 cells. Cells were treated with 10μM gossypol for different times, cytosol and mitochondrial protein were subject to SDS-PAGE followed by immunoblot with cytochrome c specific antibody. 3 注意的问题 (1) 蛋白质电泳 常用SDS-PAGE:单一亚基组成的蛋白质 非变性PAGE:多个不同亚基组成的蛋白质 Tris-Tricine胶中电泳:用于分子量小于10kDa的多肽和蛋白的电泳,能够获得较好的分离效果。 (2)转膜 戴手套,避免用手接触滤纸、凝胶和膜,因为手上的油脂会阻断转印。滤纸和膜的尺寸与凝胶大小一致 以适量的转移Buffer室温平衡滤纸、凝胶和膜15-30min,如果是PVDF膜,必须先用甲醇激活后浸泡。 方向正确:凝胶在阴极,膜在阳极 排去滤纸、胶和膜间的气泡。 电转时间:100V 1-2h,可根据蛋白分子量的大小灵活 选择转移结束后,凝胶用考马氏亮兰染色以确定转移效率膜用丽春红染色观察蛋白分子量标准的位置 (3)封闭 用5%脱脂奶粉或3%BSA (含0.1%Tween20 TBS或PBS配制) 时间:室温2h或4ºC过夜 (4)显色或显影 显色 辣根过氧化物酶:底物为DAB 碱性磷酸酶:底物为BCIP/NBT 化学发光显影 最常用。辣根过氧化物酶和碱性磷酸酶有不同的发光底物(商品化产品) 注意:化学发光前将膜用不含Tween20的TBS或PBS洗涤一次曝光的时间和显影的时间根据实际情况而定 (5)膜的再利用 化学发光后的硝酸纤维素膜用Stripping -2ME ) Buffer洗涤后(洗涤Buffer: 62.5mm pH6.7 的Tris-HCI含2%SDS和100mm的 用不同的一抗进行杂交,检测其它蛋白的表达情况。一张膜可以重复使用3-4次。碱性磷酸酶显色的膜不能再进行杂交 二、ELISA 1 原理: ELISA的基础是抗原或抗体的固相化及抗原或抗体的酶标记。结合在固相载体表面的抗原或抗体仍保持其免疫学活性,酶标记的抗原或抗体既保留其免疫学活性,又保留酶的活性。在测定时,受检标本与固相载体表面的抗原或抗体起反应。再加入酶标记的抗原或抗体,也通过反应而结合在固相载体上。此时固相上的酶量与标本中受检物质的量呈一定的比例。加入酶反应的底物后,底物被酶催化成为有色产物,产物的量与标本中受检物质的量直接相关,故可根据呈色的深浅进行定性或定量分析。测定方法具有很高的敏感度(pg-ng/ml水平),并且重复性好。 ELISA 常用的酶和底物 辣根过氧化物酶,底物为OPD, 深桔黄色 ,检测波长492nm TMB, 蓝绿色,检测波长450nm 碱性磷酸酶,底物为PNPP(对-消基苯磷酸酯), 黄色 检测波长405nm ELISA各步骤的反应时间 包被:24-36h,蛋白浓度为1-5ug/ml 封闭:37ºC 2h 或4ºC过夜(3%BSA) 样本反应时间:37ºC 45min-1h 酶标抗体反应时间: 37ºC 45min-1h 显色时间:15min(避光) 设对照 可以一次包被多块板,冻存备用 2 类型 (1)间接法测抗体 间接法是检测抗体常用的方法。其原理为利用酶标记的抗抗体,检测与固相抗原结合的受检抗体,故称为间接法。 常用于临床血清中自身抗体的检测,以及杂交瘤上清特异性抗体的筛选。如血清中PDCD5自身抗体的检测。 (2) 双抗体夹心法测抗原 是检测抗原最常用的方法。 只要获得针对受检抗原的特异性抗体,就可用于包被固相载体和制备酶结合物。 常用的组合:单克隆抗体+多克隆抗体 单克隆抗体+单克隆抗体 后一组合是两种单克隆抗体针对抗原上不同的相距较远的两个抗原决定簇,分别用于包被固相载体和制备酶结合物。 用途:测定二价或二价以上的大分子抗原,但不适用于测定半抗原及小分子单价抗原,因其不能形成两位点夹心。例如各种细胞因子的检测。 双抗体夹心法测抗原的方法: 捕获抗体包被→封闭(3%BSA)→待测抗原→洗涤(含0.1%Tween的PBS)→酶标单抗或多抗→洗涤→显色→检测 (3)竞争法测抗原 1)抗体固相测抗原 小分子抗原或半抗原因缺乏可作夹心法的两个以上的位点,因此不能用双抗体夹心法进行测定,可以采用竞争法模式。 其原理是标本中的抗原和一定量的酶标抗原竞争与固相抗体结合。标本中抗原量含量愈多,结合在固相上的酶标抗原愈少,最后的显色也愈浅。 方法:抗体包被→封闭→同时加入待测抗原和酶标抗原→洗涤→酶底物→显色→ELISA reader检测 2)抗原固相测抗原 其原理是标本中的抗原和固相抗原与一定量的抗体竞争结合。标本中抗原含量愈多,结合在固相上的抗体愈少,最后的显色也愈浅。 方法: a: 抗原包被96孔板; b:封闭; c: 待测抗原与抗体反应一定时间; d: 加入96孔板 e: 洗涤 f:加入酶标二抗 g:洗涤 h:显色和检测 (4)IgM抗体的检测 1)间接法: 间接法ELISA一般仅适用于检测总抗体或IgG抗体。如用抗原包被的间接法直接测定血清中的IgM抗体,因标本中一般同时存在较高浓度的IgG抗体,后者将竞争结合固相抗原而使一部分IgM抗体不能结合到固相上,将出现假阴性结果。 作者: yychen 时间: 2012-12-3 15:32
Saravanan R S, Rose J K C. 2004. A critical evaluation of sample extraction techniques for enhanced proteomic analysis of recalcitrant plant tissues. Proteomics, 4: 2522-2532. Shen S H, Jing Y X, Kuang T Y. 2003a. Proteomics approach to identify wound-response related proteins from rice leaf sheath. Proteomics, 3: 527-535. Shen S H, Sharma A, Komatsu S. 2003b. Characterization of proteins responsive to Gibberellin in the leaf-sheath of rice Oryza sativa L seedling using proteome analysis. Biol Pharm Bull, 26: 129-136. Chan, Z.L., Qin, G.Z., Xu, X.B., Li, B.Q., and Tian, S.P. 2007. Proteome approach to characterize proteins induced by antagonist yeast and salicylic acid in peach fruit. J. Proteome Res. 6: 1677-1688. 版主有你的这几篇参考文献的原文吗?作者: zwsyrt 时间: 2012-12-3 15:34
Here is a protocol that I developed to purify small and hydrophobic peptides (4 kDa). The end purpose was for antibody production. Peptides were passively extracted from SDS gel slices. Cells (BL21 Star™(DE3) pLysS) were lysed at room temperature using 50 mM Tris-HCl (pH 8.0) and 5 mM EDTA. Inclusion bodies were collected at 12000g for 30 min at room temperature and followed by 25000g for 10 min after resuspending in the lysis buffer. The pellet was solubilized with Laemmli loading buffer and fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) (Laemmli 1970; Schägger 1994) using a Tris-Tricine buffer. Protein containing gel slices were frozen in liquid N2 and ground into small pieces. Expressed proteins were then eluted passively at 37°C by soaking in 1% SDS (~500 μl for every 200 μl Vol gel slice) for 1.5 h with constant motion. Eluted proteins along with SDS were injected into rabbits. Surprisingly, they were alive after injection and produced great antiserum. Hope this may help someone. Cheers,作者: tudou85 时间: 2012-12-3 15:43
Protein Extraction from Drosophila Protein extracts were prepared from salivary glands dissected from third instar larvae homogenized in a buffer comprising: 20 mM Tris-HCl pH 8.0, 150 mM NaCl, 10 mM EDTA, 1 mM EGTA, 0.2% Triton X-100, 0.2% NP40, 2 mM Na3VO4, 1 mM PMSF, 1.5 μg/ml aprotinin. 作者: 66小飞侠 时间: 2012-12-3 16:00
Phenol extraction of proteins is based on the protocol described before [8], but we carried out it in the presence of SDS (designated as phenol/SDS extraction). About 0.05–0.1 g of the dry powder of leaf tissue was resuspended in 0.8 mL phenol (Tris-buffered, pH 8.0; Sigma St. Louis, MO, USA) and 0.8 mL dense SDS buffer (30% sucrose, 2% SDS, 0.1 M Tris-HCl, pH 8.0, 5% 2-mercaptoethanol) in a 2.0 mL microtube. The mixture was vortexed thoroughly for 30 s and the phenol phase was separated by centrifugation at 10 000g for 3 min. The upper phenol phase was pipetted to fresh microtubes (0.2 mL for 1.5 mL tube, 0.4 mL for 2.0 mL tube). After phase separation, white SDS complex often appears at the interphase. Be careful not to disturb the interphase by pipetting. If the recovered phenol phase is not clear, pool phenol phase together and centrifuge again. At least 5 volumes of cold methanol plus 0.1 M ammonium acetate was added to the phenol phase and the mixture was stored at 20C for 30 min. Precipitated proteins were recovered at 10 000g for 5 min, and then washed with cold methanolic ammonium acetate twice and cold 80% acetone twice. The final pellet was dried and dissolved in a buffer of choice, such as Laemmli buffer [10] or 2-DE rehydration solution (8 M urea, 4% CHAPS, 2% IPG buffer, 20 mM dithiothreitol)作者: moonlight45 时间: 2012-12-3 16:04
Preparation for gel sample Precast gels (INVITROGEN, BioRad) Reduction and alkylation before gel run Reduce with DTT, DTE or TCEP Alkylate with Iodoacetamide See sample prep handbook Disolve the sample in SDS-buffer without reducing agent no -mercaptoethanol, no DTT, no DTE Reduce with 10 mM DTT, DTE, or TCEP Never use -mercaptoethanol !!!!!! Add 1/10 of the sample volume 100 mM stock solution DTT and DTE: 5 – 10 min at 100 C TCEP: 15 min at 60 C Cool down to RT Add 20 mM Iodacetamide and incubate for 30 min at RT Load and run gel Note: o Leave one lane free between each lane to be cut o Do not overload gel o Run the gel under optimal conditions (Voltage) Coomassie blue stain (colloidal preferred) If you use own Coomassie solution – make it fresh, also destainer Silver stained gels will be rejected Stain in new 10 x 10 cm quadratic containers Do not reuse old ones (contamination) Scan gel (pack between plastic sheets to avoid contamination) Clearly label lanes/bands/areas to be cut and analysed 2-D gel spots作者: redbutterfly 时间: 2012-12-3 16:07
Preparation for gel sample Precast gels (INVITROGEN, BioRad) Reduction and alkylation before gel run Reduce with DTT, DTE or TCEP Alkylate with Iodoacetamide See sample prep handbook Disolve the sample in SDS-buffer without reducing agent no -mercaptoethanol, no DTT, no DTE Reduce with 10 mM DTT, DTE, or TCEP Never use -mercaptoethanol !!!!!! Add 1/10 of the sample volume 100 mM stock solution DTT and DTE: 5 – 10 min at 100 C TCEP: 15 min at 60 C Cool down to RT Add 20 mM Iodacetamide and incubate for 30 min at RT Load and run gel Note: o Leave one lane free between each lane to be cut o Do not overload gel o Run the gel under optimal conditions (Voltage) Coomassie blue stain (colloidal preferred) If you use own Coomassie solution – make it fresh, also destainer Silver stained gels will be rejected Stain in new 10 x 10 cm quadratic containers Do not reuse old ones (contamination) Scan gel (pack between plastic sheets to avoid contamination) Clearly label lanes/bands/areas to be cut and analysed 2-D gel spots作者: redbutterfly 时间: 2012-12-3 16:08
Preparation for gel sample
Preparation for gel sample Precast gels (INVITROGEN, BioRad) Reduction and alkylation before gel run Reduce with DTT, DTE or TCEP Alkylate with Iodoacetamide See sample prep handbook Disolve the sample in SDS-buffer without reducing agent no -mercaptoethanol, no DTT, no DTE Reduce with 10 mM DTT, DTE, or TCEP Never use -mercaptoethanol !!!!!! Add 1/10 of the sample volume 100 mM stock solution DTT and DTE: 5 – 10 min at 100 C TCEP: 15 min at 60 C Cool down to RT Add 20 mM Iodacetamide and incubate for 30 min at RT Load and run gelNote:o Leave one lane free between each lane to be cuto Do not overload gelo Run the gel under optimal conditions (Voltage) Coomassie blue stain (colloidal preferred) If you use own Coomassie solution – make it fresh, also destainer Silver stained gels will be rejected Stain in new 10 x 10 cm quadratic containers Do not reuse old ones (contamination) Scan gel (pack between plastic sheets to avoid contamination) Clearly label lanes/bands/areas to be cut and analysed 2-D gel spots作者: wmp1234 时间: 2012-12-3 16:09
湿转(wb转膜) 配置湿法电转液: 25mM Tris, 192mM glycine,20% v/v methanol, pH 8.3 3.0275 g Tris; 14.413 g Gly; 200 ml 甲醇 蒸馏水稀释到1 L. 至冰 PVDF膜:甲醇(乙醇)浸润10mi=> 纯净水 5min * 2 => 电转液 10 min 滤纸: 电转液 〉10 min Gel: 电转液 30 min 电转液倒入电泳槽中,浸泡夹心板,多孔垫片。 这几步共需要 1.5 L左右的电转液。 1) 红色(+)——〉黑色(-)依次安装 白色边盒-〉多孔垫片-〉滤纸-〉PVDF膜-〉gel-〉滤纸-〉多孔垫片-〉黑色边盒 左上角剪角,P.S安装过程尽量避免产生气泡 2) 转膜三明治装入电转移,并在电泳槽中加入预冻冰盒,电转仪入盆,用冰包埋。 3) 电流 = 凝胶面积*2 mA (30mA) 电转 2-4 小时。 参考转膜时间: 30V过夜,60V3h,100V2h 实验对象对肝癌与肝永生细胞作者: JK.jon 时间: 2012-12-3 16:09