Evaluation of DNA Yield and Purity from Fresh and Stored Blood Samples

Abstract

The objectives of this study was to evaluate the yield and purity of DNA extracted from stored and fresh blood samples. Analytical, comparative study was conducted in Khartoum state during the period from January to June, 2011.This study included 70 subjects, 35 of them were fresh blood samples and 35 of them were stored for three years. Two and half ml of whole blood was collected in ethylene di-amine tetra acetic acid (EDTA) containers so as to determine the total white blood cells count by Glacial acetic acid and to extract the genomic DNA by chelex method. the DNA concentration was measured by spectrophotometer (Biophotometer, eppendorf) at 260 nm, DNA purity was determined by the A260/A 280 ratio. The results showed that the mean concentration of DNA extracted from fresh blood samples was (220.6μ g/mL) ,which slightly higher than that extracted from stored blood samples (207.7μ g/mL), (P=0.14). The study also showed that the mean ratio of DNA extracted from fresh blood samples (1.06) was similar to stored ones (1.06), (P=0.64). Also in this study showed a weak correlation between TWBCs and the DNA concentration in fresh blood sample (r-0.08) and (P=0.64).