上游引物

两条特异性上游引物3'端第3或第4位碱基引入错配后非特异性延伸显著减少，且对PCR反应条件的严格性要求明显降低。

Non-specific primer extension was decreased remarkably after introducing a mismatch at the third or fourth 3 ′ - terminal base of allele specific primers , and the stringency of PCR reaction was cut down .

方法使用一个生物素标记的上游引物，对HBVdna及其竞争模板DNA进行不对称PCR扩增，使扩增出的单链带有生物素，并可结合在固定有链亲合素的微孔板的表面。

METHODS The HBV DNA and the competitive DNA template were asymmetrically amplified by a bio labeled upstream primer , the single string PCR products with Biotin were combined to the surface of the streptavidin fixed wells .

以基因组DNA为模板，分别加入针对K-ras第12密码子的三种主要突变方式设计的PCR上游引物R1、R2、R3和共同的下游引物R4，在taqDNA聚合酶作用下扩增相应片段。

With genome DNA as template , three upstream primers ( R1 、 R2 、 R3 ) targeting point mutation of K-ras oncogene codon 12 and common downstream primer ( R4 ) were added respectively . PCR was employed to amplify corresponding fragment with Taq DNA polymerase .

方法设计一对寡核苷酸引物，其上游引物为突变引物。

Methods A pair of primer was designed and a mismatch nucleotide was introduced in its upstream primer .

此对上游引物和下游引物分别位于剪接供体之前和剪接受体之后。

In this primer pairs , splice donor and splice acceptor were located at its downstream and upstream respectively .

目标扩增区域及内参片段的上游引物采用生物素标记，以便于液相芯片杂交检测。

Target amplified region and the forward primer of internal reference fragments were labeled with biotin in order to facilitate hybridization detection of liquid chip .

下游3个单锚定引物分别与上游10个随机引物进行30种组合PCR扩增，得到181条差异条带中，狭缝杂交证实葡萄糖上调表达的基因片段56条、下调表达的基因片段18条。

181 differentially expressed fragments were got from RT-PCR products with 3 single-base anchored primers in combination with 10 random primers . After slot blotting , we got 56 ESTs with up-regulation expression and 18 ESTs with down-regulation expression .