Degradation of buried DNA samples in different types of soil

Abstract

Biological samples buried in different types of soil are often found in crime scenes. These samples are usually highly degraded which difficult its analysis. Several factors contribute to the degradation of biological material including temperature variation, humidity, UV light and especially the presence of microorganisms. Blood was collected to three non related male donors and blood stains were made in fabrics such as jeans, cotton and lycra. Blood stains were dried at room temperature and buried in three different types of soil, to promote its degradation. It was found that samples suffer a high degradation over time which difficult their analysis. The marshy soil proved to be the most aggressive, leading to rapid degradation of the different analyzed fabrics, probably because of its high percentage of moisture and microbial proliferation