Sex determination of human blood micro-stains and single hairs using specific DNA amplification with polymerase chain reaction

Amplification of Y chromosome specific DNA in vitro enables a rapid and reliable sex determination of human minute traces such as blood stains and hairs. In presence of male DNA a band of 154 bp is visualized by agarose gel electrophoresis after amplification, this band is lacking in case of female DNA alone. Amplification of a sex independent DNA locus (such as a fragment from the alcohol dehydrogenase gene) generates identical reaction products for both sexes. This shows that the absence of a band is not due to the lack of trace DNA. It is possible to perform this technique with as little as 0.5 microliters of blood or with a single hair.