MULTIPLEXING OF Y-CHROMOSOME SPECIFIC STRS AND PERFORMANCE FOR MIXED SAMPLES

A combination of four Y-specific polymorphic STR loci was amplified si multaneously using fluorescently labeled primers. Multiplex conditions required optimization to eliminate constant bands and amplification p roducts for female DNA. A series of experiments was carried out for mi xtures of DNA from two males, and from male and female individuals for the Y-specific STRs and an autosomal locus. For the male/male mixture s amplified with the Y specific system, and amplified for an autosomal locus; the minor component in the mixture could only be identified up to a ratio of 1:10, 1:50 respectively. In male/female DNA mixtures th e Y STR alleles could be identified for the highest ratio tested, 400 pg male in DNA in 800 ng female DNA which amounts to a ratio of 1:2000 . (C) 1997 Elsevier Science Ireland Ltd.