SEPHADEX FILTRATION AND HUMAN SERUM-ALBUMIN GRADIENTS DO NOT SELECT SPERMATOZOA BY SEX-CHROMOSOME - A FLUORESCENT IN-SITU HYBRIDIZATION STUDY

Fluorescent in-situ hybridization (FISH) of decondensed sperm nuclei h as been used directly to evaluate the enrichment efficiency of human s perm separation using Sephadex gel filtration and human serum albumin (HSA) gradients. Control and processed spermatozoa were fixed and thei r nuclei decondensed. In-situ hybridization was carried out with a Y-s pecific DNA probe (DYZ1). Sephadex filtration yielded 52.5% Y-chromoso me-bearing spermatozoa, HSA separation resulted in 49.4% Y-chromosome- bearing spermatozoa and in the untreated control sample the percentage of Y spermatozoa was 49.3%. Statistical analysis revealed no signific ant differences between the selection methods employed and the control s, and no real enrichment for X- or Y-bearing spermatozoa was detected for any of the selection methods assayed. The usefulness of the proto cols reported for selection of spermatozoa by sex chromosome in couple s at risk for X-linked diseases is discussed.