The blood specimens were centrifuged at
2,000 3 g for 10 min to obtain the plasma. Then, 1 ml of the plasma was added
to a PCR tube and the DNA was extracted by adding 20 ml of Genereleaser
(Bioventures, Murfreesboro, Tenn.) in accordance with the manufacturer’s protocol.
PCR mix (see below) was added to a final volume of 100 ml. The PCR assay
was done under the conditions described below.