Comparative analysis of reagent kits for DNA extraction from dry blood stains

Abstract

Neonatal screening is a mandatory newborn screening procedure that detects the presence of genetic diseases. Dry blood stains are used for mass screening of children. This technology is the most affordable and convenient for the transportation and storage of biological material. DNA extraction is one   of the important steps in molecular diagnostics, the accuracy of which is particularly important in genetic analysis. Different DNA extraction kits offer different protocols and reagents, which may vary in efficiency and quality of extraction.The aim of our work was to perform a comparative analysis of reagent kits for DNA extraction from dried blood spots.The materials were dried blood drop samples on Guthrie cards obtained from healthy preterm infants on day 3-4 of life as part of a newborn screening program.The study methods included spectrophotometric analysis to determine the concentration and purity of DNA, the simplicity of protocols, the duration of isolation, and the possibility of automating the process were also evaluated. The efficiency of DNA isolation using different reagent kits was additionally monitored by real-time PCR results using a test system to assess the level of TREC and KREC in peripheral blood, since quantitative analysis requires more attention to the material under study.In assessing the purity of the nucleic acid extracted using four kits analyzed, successful deproteinization of DNA samples and relative purity could be observed. The average DNA purity for the “Extra-DNA-Bio” set was 2.2±0.23, for “EXTRA-prep PS” – 1.89±0.23, for “MagnoPrime UNI” with manual and automatic isolation – 2.31±0.21 and 2.85±0.09, respectively. The average DNA concentration for the Extra-DNA-Bio kit was 15.28 μg/mL, for the EXTRA-Prep PS kit it was 16.26 μg/mL, and for the MagnoPrime UNI for manual and automated isolation it was 62.5 μg/mL and 102.28 μg/mL, respectively. According to the applied Kraskell-Wallis criterion and Dunn’s test, significant differences in both TREC and KREC parameters are present between the group of DNA samples extracted using the “MagnoPrime UNI” reagent kit for manual extraction and the groups of samples extracted by other methods (“MagnoPrime UNI” for automatic extraction) or “Extra-DNA-Bio” and “EXTRA-Prep PS” kits.In the course of the present study, four comparable reagent sets demonstrated a high level of convergence of the obtained data, satisfying all the necessary parameters for further molecular genetic analysis, can be used for neonatal screening and in other areas of research requiring DNA extraction from a dried blood spots.