Preimplantation diagnosis: 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 spermnuclei has been used directly to evaluate the enrichment efficiencyof human sperm separation using Sephadex gel filtration andhuman serum albumin (HSA) gradients. Control and processed spermatozoawere fixed and their nuclei decondensed. In-situ hybridizationwas carried out with a Y-specific DNA probe (DYZ1). Sephadexfiltration yielded 52.5% Y-chromosome-bearing spermatozoa, HSAseparation resulted in 49.4% Y-chromosome-bearing spermatozoaand in the untreated control sample the percentage of Y spermatozoawas 49.3%. Statistical analysis revealed no significant differencesbetween the selection methods employed and the controls, andno real enrichment for X-or Y-bearing spermatozoa was detectedfor any of the selection methods assayed. The usefulness ofthe protocols reported for selection of spermatozoa by sex chromosomein couples at risk for X-linked diseases is discussed.