混合生物样品的组分分析及其STR基因型判定

Study of Component Proportion and STR Genotyping of Mixed Biological Samples

目的应用荧光标记STR多基因座联合检测技术对混合生物样品较少组分最低比例检出限和STR基因型的判定进行研究。方法 将已知浓度的人标准细胞系DNA:9947A和K562分别按照1:1、1:4、1:9、1:19、1:39、1:59、1:79和1:99比例混合后作为扩增模板,应用Profiler plus试剂盒对D3S1358、VWA、FGA、D8S1179、D21S11、D18S51、D5S818、D13S317、D7S820和性别鉴定基因座检验。结果在比例为1:19时能明确判定两个体各基因座基因型,且两样品基因型结果峰高平均值之比与样品浓度之比正相关。结论应用荧光标记STR多基因座联合检测技术可以对一定比例的混合生物样品进行STR基因型判定,并对其混合比例状况进行大致推断。

Objective Study of minimal proportion of minor component to be detected in mixed biological samples and the interpretation of genotyping result. Methods Standard cell line DNA 9947A and K562 were chosen as samples in the study as their concentration is well known and certain. We prepared templates for STR multiplex test by mingling 9947A and K562 according to different ratios: 1: 1, 1: 4, 1: 9,1: 19,1: 39, 1:59, 1:79 and 1:99. The templates were submitted to amplification by ABI profiler plus kit. Results Unambiguous combination genotypes were obtained when the minor part was more than 5% , and in this situation, the ratio of average peak height of the two components is just positive relevant to that of template concentration. Conclusion STR multiplex examination is an ideal method to study the genotype of each component and their combination ratio in a mixed biological sample with certain composed proportion.