The frequency of false-positive and false-negative results in the detection of Y-chromosomes in interphase nuclei.

In blood smears from 527 females and 457 males examined for the presence of Y chromosomes in interphase nuclei, 0.6% false-positive results and 11% false-negative results were found. There was a clear tendency for the false-negative results to occur among those with small fluorescent or non-existing bands on the Y chromosome. The three false-positive females all had fluorescent chromosomal variants. In a comparison between female samples with and without chromosomal variants respectively, the former showed significantly higher false Y-body counts. There was a decrease in the number of Y-bodies with increasing age. There were no significant differences between staining with 0.1% Quinacrine mustard and 0.1% and 1% Mepacrine. This study provides a more solid basis for the use of Y chromosome detection in forensic medicine, for screening purposes etc.