Walker A H, Najarian D, White D L, Jaffe J F, Kanetsky P A, Rebbeck T R
Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics and Cancer Center, University of Pennsylvania School of Medicine, Philadelphia 19104-6021, USA.
Environ Health Perspect. 1999 Jul;107(7):517-20. doi: 10.1289/ehp.99107517.
Studies in molecular and genetic epidemiology require a high-throughput, low cost, and reliable means of genomic DNA collection. Buccal (cheek) swabs have been proposed as a means of achieving these goals, but there is little information about the practical application of this approach. From January 1995 to December 1997, we processed 995 buccal swabs for use in polymerase chain reaction (PCR)-based genotype assays in the context of ongoing molecular epidemiologic studies. Six hundred forty-seven of these swabs were processed immediately after collection and 348 were received by mail. We were able to obtain at least one genotype from 99.7% (645 of 647) of fresh-processed and 97.4% (330 of 339) of mailed biosamples. A PCR success rate of 90.3% (2,546 genotypes from 2,819 assays) was achieved. Genotypes were obtained from 96.1% (1, 865 genotypes from 1,941 assays) of fresh-processed biosamples and 77.6% (681 genotypes from 878 assays) of mailed biosamples. PCR success rates at any single locus ranged from 92.6 to 98.8% (fresh-processed) and 75.5 to 79.6% (mailed). The PCR success rate among fresh-processed biosamples was significantly higher than among mailed biosamples (Fisher's exact test p < 0.0001), and more attempts were required to obtain a successful PCR result for mailed biosamples as compared to fresh-processed biosamples. For one locus (CYP3A4), a subset of mailed biosamples was purified if two or more PCR failures occurred. Additional genotypes were obtained in 58.3% of these previously failed biosamples. Time from biosample receipt to DNA extraction had no effect on PCR success. After storage of processed biosamples for as long as 3 years, there was no appreciable decrease in the rate of PCR success. These results suggest that adequate DNA for PCR-based applications can be obtained from buccal swabs, but sampling or processing considerations may be important in obtaining optimal results.
分子与遗传流行病学研究需要一种高通量、低成本且可靠的基因组DNA采集方法。口腔（颊部）拭子已被提议作为实现这些目标的一种手段，但关于这种方法的实际应用信息却很少。从1995年1月至1997年12月，在正在进行的分子流行病学研究中，我们处理了995份口腔拭子用于基于聚合酶链反应（PCR）的基因型检测。其中647份拭子在采集后立即进行处理，348份是通过邮寄收到的。我们能够从99.7%（647份中的645份）的新鲜处理样本和97.4%（339份中的330份）的邮寄生物样本中获得至少一种基因型。PCR成功率达到了90.3%（2819次检测中获得2546个基因型）。从96.1%（1941次检测中获得1865个基因型）的新鲜处理生物样本和77.6%（878次检测中获得681个基因型）的邮寄生物样本中获得了基因型。任何单个位点的PCR成功率在新鲜处理样本中为92.6%至98.8%，在邮寄样本中为75.5%至79.6%。新鲜处理生物样本中的PCR成功率显著高于邮寄生物样本（Fisher精确检验p<0.0001），与新鲜处理生物样本相比，邮寄生物样本需要更多尝试才能获得成功的PCR结果。对于一个位点（CYP3A4），如果出现两次或更多次PCR失败，对一部分邮寄生物样本进行了纯化。在这些之前失败的生物样本中，58.3%获得了额外的基因型。从收到生物样本到进行DNA提取的时间对PCR成功率没有影响。在处理后的生物样本储存长达3年后，PCR成功率没有明显下降。这些结果表明，可以从口腔拭子中获得足够用于基于PCR应用的DNA，但在获得最佳结果时，采样或处理方面的考虑可能很重要。
