点击“submit”进入下面的页面。
其中在Select YES to Amplify a region with EXACT endpoints of the DNA sequence entered NO YES这一项中,一定要选择yes,其他的各项目,大家可以点击查看说明,也都是非常的好理解。暂时,我们先不要改软件自设的默认值,直接submit
然后点击“This is the BEST pair of primers”就得到了设计好的引物。而且也会显示出“The sequence of DNA that will be amplified by these primers is ”如果你不放心,你可以将该序列和你的原始序列比较一下,不会有问题的了。
There were 1 forward primers in the valid range for GC content.
There were 4 reverse primers in the valid range for GC content.
There were 1 forward primers in the valid range for melting temperature.
There were 0 reverse primers in the valid range for melting temperature.
ERROR
The Tm range was too stringent, no primers were found in that range作者: 小鼹鼠 时间: 2011-8-13 16:47
我们可以改两个地方,第一,Optimum primer length: Minimum length: Maximum length:中,我们可以将Maximum length改成一个更大的值,例如35;Minimum GC改成20,然后submit,
可是我们发现还是有问题。
There were 0 forward primers in the valid range for GC content.
ERROR
The GC range was too stringent, no primers were found in that range
然后我将Minimum GC: 40 Maximum GC: 70
出来以下结果Primers for PCR
There were 39 forward primers in the valid range for GC content.
There were 66 reverse primers in the valid range for GC content.
There were 19 forward primers in the valid range for melting temperature.
There were 11 reverse primers in the valid range for melting temperature.
There were 19 forward primers with valid self anneal values.
There were 11 reverse primers with valid self anneal values.
There were 19 forward primers with valid self end anneal values.
There were 11 reverse primers with valid self end anneal values.
There were 209 pairs of valid primers.
This is the BEST pair of primers
List of all valid pairs of primers
然后我用This is the BEST pair of primers是不是就ok了作者: 小鼹鼠 时间: 2011-8-13 16:58
Pair-Anneal: 20
Pair-End-Anneal: 6
Total valid primer pairs: 1
谢谢楼主,请问下设计出来的引物如上,Tm值是否偏低?作者: 小鼹鼠 时间: 2011-8-13 17:07
楼主你好!这个在线软件看起来比Oligo6.72、primer等软件简单,但该软件似乎只考虑了引物的长度范围、引物的退火温度、引物的GC含量范围,而没有关于引物之间能否形成二聚体方面的信息。而Oligo6.72评价引物则采取了多方面的评价,包括二聚体等信息,但缺点是提供了很多对引物,没有提供最好的,选择哪一对都要靠自己把握。
比如我想设计wnt3a mRNA的引物,基因系列见:cuturl('http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?val=NM_033131.2') 。我把该基因序列copy进去后,提示The GC range was too stringent, no primers were found in that range。按照楼主提供的方法降低minimum GC值但仍然出现该提示语,所以我将maximum GC改成90,此时出现The Tm range was too stringent, no primers were found in that range,故将Maximum Tm改成70,此时出现The end anneal range was too stringent, no primers were found in that range,一直找不到--- 作者: 小鼹鼠 时间: 2011-8-13 17:07
我按你的方法,在Select YES to Amplify a region with EXACT endpoints of the DNA sequence entered NO YES这一项中,选择yes则得不到结果,但是选择no每次都能得到结果,选择no得到的结果有什么问题?作者: 小鼹鼠 时间: 2011-8-13 17:08
楼主,您好!
我看了您介绍的引物在线设计软件,的确好用,但是由于我要扩的部分GC含量相对较高,照您说的“在Select YES to Amplify a region with EXACT endpoints of the DNA sequence entered NO YES这一项中,一定要选择yes”,我点YES时,总提示我GC含量范围不对,一次误操作没点YES,默然的NO,竟然出了很多引物,我想问:为什么一定要点YES?是不是点YES,设计出的引物扩出来的是我输入的整个序列长?请解答一下,谢谢您了 。 作者: 小鼹鼠 时间: 2011-8-13 17:13
楼主你好!我的片断P很久了,都没有出来,估计就是属于那种极品,后来我按你的方法试了,但改了很多次参数都不行,楼主能否帮看看,要怎么改合适啊!万分感谢!
Get primers
Primers for PCR
There were 1 forward primers in the valid range for GC content.
There were 66 reverse primers in the valid range for GC content.
There were 0 forward primers in the valid range for melting temperature.
ERROR
The Tm range was too stringent, no primers were found in that range
你好!上面的结果在第二步中没点yes得到的,点过yes就得到下面的结果,请帮忙分析一下,怎么改参数,谢谢!
Primers for PCR
There were 4 forward primers in the valid range for GC content.
There were 4 reverse primers in the valid range for GC content.
There were 1 forward primers in the valid range for melting temperature.
There were 0 reverse primers in the valid range for melting temperature.
ERROR
The Tm range was too stringent, no primers were found in that range作者: 小鼹鼠 时间: 2011-8-13 17:22