Abstract
We studied unrelated male donors (n = 141) living in Cantabria, a region in northern Spain. DNA was extracted from peripheral blood by using the Qiagen blood kit (Qiagen, Hilden, Germany). Loci of interests in the X-chromosome (DXS9895, GATA172D05 and DXS9898) were amplified in a single PCR with primers of published sequences (1-3). PCR conditions consisted of an initial denaturation step at 94° for 10 min, followed by eight cycles with denaturation at 94° for 1 min, annealing at decreasing temperature between 62° and 59° (1° decrease every two cycles) and extension at 72° for 1 min. Then 24 cycles at 94° 1 min, 58° 1 min, 72° 1 min; followed by a final extension at 72° for 30 min. PCR products were analyzed by capillary electrophoresis (ABI310, Applied Biosystems), with sequenced controls. Allele designation was as reported previously (1,2).