Use of potassium iodide to extract genomic DNA from cryopreserved peripheral blood

Objective To assess the yield and quality of genomic DNA from cryopreserved peripheral blood using potassium iodide.Methods We used potassium iodide to extract genomic DNA from 400 μL of cryopreserved blood (preservation at -20℃ for 6 months) and 200ul of fresh blood (preservation at 4℃ for less than 1 week).The concentration and purity of the extracted DNA from the two different blood samples were compared;and the DNA was used as a template to amplify CYP2C19 gene by PCR.Results By increasing the amount of blood samples,we could enhance the yield of genomic DNA from cryopreserved peripheral blood,but the DNA purity was lower than that from fresh blood.Conclusions According to the purpose and requirements of the use of potassium iodide to extract DNA,we should choose an appropriate preservation method for blood samples.