DNA persistence in soft tissue comparing vodka and absolute ethanol

Abstract

Successful DNA analysis of human remains relies on the collection and preservation of biological material. Low temperatures are typically used to preserve soft tissues; however, this is not always available, for example, after mass disasters and conflict, where the infrastructure has been damaged. Lysis buffers and absolute ethanol have also been shown to be effective at preserving material, but again are not always readily available. This study assess the use of drinking alcohol as an alternative preservative solution for muscle tissue storage. Pig muscle was incubated for up to 42 days at different temperatures (−20 °C, 25 °C, and 37 °C) with 95% ethanol, 37.5% ethanol, vodka (37.5%), and no preservative. Samples were collected weekly and analysis was based on agarose gel electrophoresis, DNA quantitation and amplification success of a multiplex with amplicons between 70 bp and 384 bp. Samples incubated with 37.5% ethanol and vodka had high molecular weight DNA and all samples incubated with preservative solutions generated complete profiles until the last collection point, while samples left untreated had drop-outs after 21 days at 25 °C and 37 °C.