Park Su Jeong, Kim Jong Yeol, Yang Young Geun, Lee Seung Hwan
DNA Analysis Lab, Forensic Science Division, Supreme Prosecutors' Office, Seocho-Gu, Seoul, Korea.
J Forensic Sci. 2008 Mar;53(2):335-41. doi: 10.1111/j.1556-4029.2008.00666.x.
The DNA purification step has been thought to be essential for typing of STR DNA. However, this process is time-consuming, and there is a risk of unexpected cross-contamination during purification. We report a new method for direct short tandem repeat (STR) amplification using a newly developed direct PCR buffer, AnyDirect, which can amplify STR loci from whole blood and blood- or saliva-spotted FTA cards without DNA purification. The autosomal and Y chromosomal STR loci were analyzed for whole blood and blood or saliva spots of random individuals, followed by comparison of the results with those of corresponding purified DNA. The results from whole blood and blood spots showed perfect concordance with those from purified DNA without allele or locus drop-out. However, in the case of saliva spots, no amplification or locus drop-out was observed in some of the samples, which offers a topic for further study. Additionally, some commercial hot-start DNA polymerases other than AmpliTaq Gold DNA polymerase were also found to be compatible with this buffer system. Therefore, this direct PCR buffer was demonstrated to be useful for fast forensic DNA analysis or criminal DNA databases for which there is no need to store DNA samples.
DNA纯化步骤一直被认为是STR DNA分型的必要条件。然而，这个过程耗时且在纯化过程中存在意外交叉污染的风险。我们报告了一种使用新开发的直接PCR缓冲液AnyDirect进行直接短串联重复序列（STR）扩增的新方法，该缓冲液可在不进行DNA纯化的情况下从全血以及血斑或唾液斑的FTA卡中扩增STR位点。对随机个体的全血、血斑或唾液斑进行常染色体和Y染色体STR位点分析，然后将结果与相应纯化DNA的结果进行比较。全血和血斑的结果与纯化DNA的结果完全一致，没有等位基因或位点缺失。然而，对于唾液斑，在一些样本中未观察到扩增或位点缺失，这为进一步研究提供了一个课题。此外，还发现除了AmpliTaq Gold DNA聚合酶之外的一些商业热启动DNA聚合酶也与该缓冲液系统兼容。因此，这种直接PCR缓冲液被证明对于快速法医DNA分析或无需存储DNA样本的刑事DNA数据库很有用。
