Comparison of thris-EDTA and threhalose on DNA quality under different storage conditions "medico-legal view"

ABSTRACT

DNA storage is important to ensure integrity of DNA sample and maintain its availability while investigations. The best known condition for storage of DNA samples is by using Tris-EDT [TE]; as preservative agent, stored at -80[degree sign]C. A potential alternative to TE is trehalose which could stabilize any biological molecule at room temperature [RT]. Assessment of the optimal storage conditions which maintains quality of blood DNA samples with economical advantage. A case-control study using 8 groups of human blood DNA stored at 2 different temperatures [-80 [degree sign]C,RT] and preserved by using TE and trehalose. The effectiveness of storage conditions were tested at certain intervals [at set-up then after 3 and 6 month] using PCR assay of 18s ribosomal gene to evaluate DNA quality. DNA was assessed by running yield gels. PCR success rate were 43.8% and 62.8% using TE and trehalose respectively. After 6 months, PCR success rate were 25% for TE and 62.5% for trehalose [p<0.05]. The relative risk [RR] of poor quality associated with using trehalose is 0.4. Trehalose serves as an alternative to expensive freezer storage. It has a DNA protective effect which helps in preservation even trace DNA while judicial proceedings continue