中文摘要：

目的构建人大肠癌细胞cDNA表达文库，用抗人大肠癌噬菌体抗体CH209筛选新的大肠癌抗原基因。方法抽提人大肠癌细胞HRT-18的总RNA后分离mRNA，利用SMART（Switching Mechanismat5^th end of RNA Transcript）技术合成cDNA，与λTripIEx2载体连接包装成cDNA文库。测定原始文库的滴度和文库重组率，鉴定插入片段的大小，测定扩增文库库容量并鉴定CH209筛选的阳性克隆。结杲原始文库滴度为6．5×10^6 pfu／mL，重组率为97％；插入片段的大小介于0．5—2．0kb之间；扩增文库滴度为1．1×10^9 pfu／mL，筛选后获得10个阳性克隆，代表10个抗原基因，其中5个与已知基因高度同源，3个与已知基因部分同源，2个是新基因。结论成功构建了人大肠癌细胞的cDNA文库；用CH209筛选得到10个大肠癌相关抗原基因，有2个是新基因。

英文摘要：

Objective The cDNA expression library, which was constructed with human colorectal cancer cell HRT-18, was screened with the phage antibody CH209 in order to find novel antigen genes of colorectal carcinoma. Methods Total RNA was extracted from cell HRT-18 and mRNA was isolated from total RNA and then double strand cDNA was synthesized by SMART technique, cDNA was ligated into λ TriplEX2 vector and then was packaged into λ phage in vitro. The primary library was titrated and the percentage of recombinant clones were determined. The length of cDNA inserts was tested for ligation efficiency. The library was screened with phage fusion antibody CH209 and the sequences of the reacted clones were determined. Results The primary library consisted of 6.5 × 10^6 pfu/mL, and the percentage of recombinant clones was 97%. The length of cDNA inserts was 0.5--2.0 kb. The titer of the amplified cDNA library was 1.1 × 10^9 pfu/mL. Ten positive clones were obtained and derived from ten different genes. Five of these genes were high homologous to genes known in GenBank, and there were also three genes with low homology to genes known in GenBank. The remainder two genes might be novel genes by matching in GenBank with BLAST software. Conclusion The quality of the constructed cDNA library from human CRC cell HRT-18 is excellent. Ten positive clones were obtained and two of them may be novel genes.