Donors left over blood as a source of genomic DNA for genetic studies

Abstract

Screening a mutation, polymorphism or genetic studies in a population involving a large sample size and costing. Left over blood from donors can be a genomic DNA (gDNA) source without collection cost. Thus, this article report the mean concentration, yield and purity of gDNA extracted from donors left over blood and the association of gDNA yield with age, gender and blood type of donors. Sample size was calculated using PS software

A Comprehensive Comparison of DNA Extraction Using Fresh and Stored Bloods in Molecular Hematology Diagnostic Study

“…Nucleo Spin® Blood L kit (Macherey-Nagel, Germany) was used to isolated the DNA fromfresh and stored blood samples.The protocols were according to the manufacturer's instructions 21 ; Two ml of fresh bloods were added with 150 µl Proteinase K and 2.0 ml of buffer BQ1; The samples were vigorously vortexed for 10 seconds before incubated at 56°C for 20 minutes and vortexed once during the incubation;The samples were cooled down to roomtemperature for 10 minutes before the addition of 2.0 ml of absolute ethanol and laterinverted 10 times;Threeml of samples (lysate) were loaded into thecolumn located in a collection tube and centrifuged for three minutes at 4,500 xg; All the remaining lysate samples were loaded into the respective columnand centrifuged for another five minutes at 4,500 xg; The columns were then inserted into anew 15 ml collection tubeand centrifugedfor two minutes at 4,500 xgafter the addition of 2.0 ml of buffer BQ2;For a second wash, another 2.0 ml of buffer BQ2 was added to thecolumns and centrifuged for 10 minutes at 4,500 xg; The columns were again inserted into a new 15ml collection tube and 200 µl of preheated buffer BE at 70°C was directly applied to the centerof the columns;The columns were incubated for five minutes at roomtemperature, followed by centrifugation for two minutes at 4,500 xg.For stored bloods, 1.0 ml of phosphate buffered saline (PBS) (Qiagen, USA) was added into one ml of samplesbefore the addition of 150 µl of Proteinase K and 2.0 ml of buffer BQ1 (Macherey-Nagel, Germany).There are two differences in isolating the DNA from stored bloods; 1)Incubation time at 56°C with Proteinase K and buffer BQ1was 30 minutes instead of 20 minutes for fresh bloods; 2) During the incubation, the storedbloods were vortexed twice instead of once for fresh bloods. The rest of the steps were the same as in extraction of fresh bloods.The final volume of DNA samples in buffer BE was 200 µl with dissimilar concentrations.…”