Comparison of DNA extraction methods for samples from old blood collections

In this study, DNA was extracted from whole blood which had been collected and stored at -20°C for 5-18 years, with the aim of determining the most suitable commercial DNA extraction kit for this purpose. DNA from nine cord blood samples collected in 1999, 2001 and 2012, with low blood volumes (<1 ml), and a partly dried adult blood sample collected in 2003, having a large blood volume (6 ml) was extracted using four different DNA extraction kits: Quick-DNA Miniprep Plus kit, DNeasy Blood & Tissue kit, MagAttract HMW DNA kit and QIAamp Blood Maxi kit. We concluded that high-quality DNA can be extracted from whole blood sample collections which have been stored for even up to 18 years in a biobank at -20°C.