中文摘要：

采用L9（3^4）正交实验法，对与人神经系统疾病相关的DNA重复序列PCR扩增体系中的模板DNA浓度、Taq酶浓度、引物浓度、dNTP浓度4种影响因素进行了优化筛选，发现引物浓度对扩增结果影响的显著性最大．在此基础上进行了引物浓度单因素实验，得到最优DNA重复序列PCR扩增体系在25μL反应体系中各组分的最适浓度分别为：模板3ng／μL、Taq酶0．75U、dNTP0．25mmol／L、引物0．31μmol／L通过优化前后反应体系的对比，扩增目的产物的量均有较大程度的提高．该优化体系的建立为进一步研究与人遗传病相关的DNA重复序列的结构特性及阐明该类遗传疾病的分子机理奠定了基础．

英文摘要：

The effects of four factors, such as the concentration of template DNA, Taq DNA polymerase, primers and dNTP ,were investigated using orthogonal experiment method to optimize the PCR reaction system of DNA repeat sequence. The result indicated that the concentration of primers had great effect on the result of PCR anaplification. Based on this result, the single factor experiment of the con- centration of primer was carried out and the optimal concentration of the components in PCR 25μL reaction system , which includes 3 ng/μL template DNA, 0.75 U Taq DNA polymerase, 0.25 mmol/L dNTP and 0.3 μmol/L primers , was obtained. Comparing the results of the optimized system with the reference system, the target product was increased obviously. The optimized system was the basis of the further investigation on structural feature of DNA repeat sequences and molecular mechanism of this kind of genetic diseases.