中文摘要：

应用噬茵体c端展示系统构建的cDNA文库缺乏开放阅读框筛选机制，文库中多数噬茵体克隆展示框外非天然短肽，给后期蛋白质的筛选带来了不便．为实现噬菌体的ORF筛选功能，利用PCR技术对已有载体T7Selectl0．3b进行改造，在MCS处外源cDNA插入位点的3’端引入6聚组氨酸筛选标签，经包装后挑取成功表达的单克隆构建肺癌cDNA文库．经镍柱亲和层析后，收集文库中表达组氨酸的克隆，利用化学发光免疫试验进行筛选效果鉴定．结果显示，改造的新型载体可成功表达组氨酸标签，以此构建的肺癌cDNA文库经筛选后，含ORF插入的克隆由筛前的6％提高至70％，本研究为提高cDNA文库的质量提供了一种简便可行的方法．

英文摘要：

The commercially available cDNA T7 phage library is constructed using C-terminal display mechanism, which contains inadequate open reading frame （ORF） expressed protein epitopes. To improve the selection of ORF proteins, we modified the existing phage vector T7Selectl0-3b by inserting 6 x His-tag genes into the multiple cloning sites （MCS） at the 5＇ terminus by PCR. The obtained phage clone expressing His-tag was used for construction of a display library. The cDNA was extracted from the human lung cancer tissues and inserted into the His-tag modified vector. The packaged phages with ORF inserts were enriched by Ni-chelating affinity chromatography, and then screened by chemiluminescence immunoassay. The result showed that the 6 x His-tag allowed the enrichment of expressed peptides with an increased from 6 % to 70 % as compared to unselected the library. Our His-raged phage library provided a convenient and practical method to improve the ORF selection.