Efficiency of MicroSort flow cytometry for producing sperm populations enriched in X- or Y-chromosome haplotypes: a blind trial assessed by double and triple colour fluorescent in-situ hybridization

Using fluorescent in-situ hybridization (FISH) we have evaluated, on ablind basis, the efficiency of flow cytometry to separate human X- andY-chromosome bearing spermatozoa. Our data demonstrate that humanspermatozoa can be sorted to a purity of 80-90% for X spermatozoa and of60-70% for Y spermatozoa. Our results using triple FISH fully agree withthe sorting treatment used in each case and corroborate the efficiency ofthe flow sorting technique for sperm sex selection. In these limitedsamples (200-500 sperm/donor), the frequencies of disomic or diploidspermatozoa were not increased when comparing the sorted samples withunselected samples or with our control series.