Handt O, Krings M, Ward R H, Pääbo S
Zoological Institute, University of Munich, Germany.
Am J Hum Genet. 1996 Aug;59(2):368-76.
DNA was extracted from approximately 600-year-old human remains found at an archaeological site in the southwestern United States, and mtDNA fragments were amplified by PCR. When these fragments were sequenced directly, multiple sequences seemed to be present. From three representative individuals, DNA fragments of different lengths were quantified and short overlapping amplification products cloned. When amplifications started from <40 molecules, clones contained several different sequences. In contrast, when they were initiated by a few thousand molecules, unambiguous and reproducible results were achieved. These results show that more experimental work than is often applied is necessary to ensure that DNA sequences amplified from ancient human remains are authentic. In particular, quantitation of the numbers of amplifiable molecules is a useful tool to determine the role of contaminating contemporary molecules and PCR errors in amplifications from ancient DNA.
从美国西南部一个考古遗址发现的约600年前的人类遗骸中提取了DNA，并通过聚合酶链反应（PCR）扩增了线粒体DNA（mtDNA）片段。当直接对这些片段进行测序时，似乎存在多个序列。从三个具有代表性的个体中，对不同长度的DNA片段进行了定量，并克隆了短的重叠扩增产物。当扩增从少于40个分子开始时，克隆包含几种不同的序列。相比之下，当由几千个分子引发扩增时，获得了明确且可重复的结果。这些结果表明，要确保从古代人类遗骸中扩增出的DNA序列是真实的，需要比通常更多的实验工作。特别是，对可扩增分子数量的定量是确定当代污染分子和PCR错误在古代DNA扩增中所起作用的有用工具。
