X- and Y-chromosome-bearing sperm selection and detection methods. A review

The ability to preselect the sex of human offspring would have a significant impact on the preventing of sex chromosome-linked diseases and on human reproduction. Numerous methods have been reviewed including: Sephadex gel filtration, centrifugation in density gradients, separation in albumin gradient, laminar flow, counterstreaming centrifugation, free-flow electrophoresis, galvanic method, two-phase system separation, flow cytometry, immunological exclusion. None of these methods seems to be ideal. Results obtained with the use of the most of them are contradictory, the others still need reliable confirmation. Part of the controversy related to the efficacy of methods aimed at sex selection may be due to the lack of appropriate and widely used techniques of X- and Y-chromosome bearing sperm detection. Fluorescent in situ hybridization appears to be the most suitable among the sperm sex chromosome detection techniques described in this review. Others, like quinacrine staining method, human sperm/hamster oocyte penetration assay, microinterferometry, cytometry, and polymerase chain reaction exhibit more or less disadvantageous features, which limit their application.