Legrand Beatrice, Mazancourt Philippe de, Durigon Michel, Khalifat Véronique, Crainic Karine
Département universitaire de médecine légale et droit médical, Université René Descartes, 45, rue des Saint Pères, 75270 Paris Cedex 06, France.
Forensic Sci Int. 2002 Feb 18;125(2-3):205-11. doi: 10.1016/s0379-0738(01)00641-7.
Formalin-induced DNA degradation was studied at different fixation times (3, 7, 16 and 32 days) each on 10 formalin fixed paraffin embedded tissues (FFPET) stored for 15 years at room temperature. The four different extraction protocols used in this study showed that Chelex100 extracts performed the best at 3 and 7 days of formalin fixation (DFF) (with regard to the quantity and the quality of the DNA). However, Qiamp extracts showed better results for long sized alleles, as well for single polymerase chain reaction (PCR) amplifications after 16 and 32 DFF, as for multiplex PCR at shorter fixation times. DNA degradation is expressed by the size of the amplified alleles, only 100 bp templates surviving after 32 DFF (AMG locus). Single locus amplifications (CD4 and FES/FPS alleles) performed better than multiplex PCR (ProfilerPlus), with nearly 100% positive results at 7 DFF. In both types of amplifications, the success rate decreased proportionally with the time of formalin fixation and, consequently, with the size of the required DNA template.
研究了在不同固定时间（3天、7天、16天和32天）对10个在室温下保存15年的福尔马林固定石蜡包埋组织（FFPET）进行福尔马林诱导的DNA降解情况。本研究中使用的四种不同提取方案表明，在福尔马林固定3天和7天（DFF）时，Chelex100提取物在DNA数量和质量方面表现最佳。然而，Qiamp提取物在福尔马林固定16天和32天后对长片段等位基因以及单聚合酶链反应（PCR）扩增效果更好，在较短固定时间下用于多重PCR时也是如此。DNA降解通过扩增等位基因的大小来表示，福尔马林固定32天后只有100 bp的模板存活（AMG位点）。单基因座扩增（CD4和FES/FPS等位基因）比多重PCR（ProfilerPlus）表现更好，在福尔马林固定7天时阳性结果接近100%。在两种扩增类型中，成功率均随福尔马林固定时间成比例下降，因此也随所需DNA模板大小下降。
