DNA Extraction from Plasma and Serum

There are occasions where the only materiel available on a patient is stored plasma or serum samples. In normal individuals, the amount of DNA in these samples is very low but sufficient to serve as template for PCRs. Moreover, increased amounts of circulating DNA have been found in a variety of disorders, including cancer, autoimmune disease, and infection. Additionally, small amounts of fetal DNA have been detected in maternal plasma/serum during gestation. We have used the following protocol to successfully genotype archival plasma samples.