DYS19 and amelogenin in artificial blood stains with defined amounts of male and female cells.

The sensitivity of the DYS19 and the amelogenin STR systems for amplifying Y-specific fragments was assayed using artificial bloodstains with varying amounts of male and female (non-template) DNA in different ratios. The study confirmed the high sensitivity of both systems in detecting male-specific PCR fragments in stains containing 10-25 template molecules even in the presence of large amounts of female DNA in the mixture by silver-stain detection. However, blood mixtures which contain less than 10% male cells could be reliably typed only when at least 100 template molecules were present in the artificial bloodstain, due to increasing amounts of hemoglobin from the female blood which is a PCR inhibitor.