FLUORESCEIN ISOTHIOCYANATE CONJUGATE-WHEAT GERM AGGLUTININ STAINING OF HUMAN SPERMATOZOA AND FERTILIZATION IN-VITRO

Objective: To determine the sensitivity and clinical significance of f luorescein isothiocyanate wheat germ agglutinin (FITC-WGA) staining of human spermatozoa. Design: Percentage FITC-WGA staining was assessed in the different morphological zones of human spermatozoa and compared with fertilization rates of metaphase II oocytes in vitro. Patients: Spermatozoa and oocytes were obtained from normospermic (n = 12) and m ale factor patients (n = 15) attending the Tygerberg Hospital's IVF cl inic. Main Outcome Measures: Aliquots of swim-up spermatozoa used in t he IVF laboratory were examined for the presence and morphological loc alization of WGA receptors. Fertilization rates were expressed as the percentage of metaphase II oocytes with successful fertilization. Resu lts: Human spermatozoa capacitated in vitro for use in an IVF program showed variations in the percent positive staining of the acrosomal re gion which correlated with IVF rates in both patient groups studied. V alues of FITC WGA acrosomal staining of <35% corresponded with IVF rat es of <50% whereas >35% WGA acrosomal staining corresponded with IVF r ates greater than or equal to 50%. Significant differences between acr osomal and equatorial region staining from normozoospermic samples and male factor samples also were observed. Conclusion: The results indic ate the practical use of the WGA assay for molecular assessment of mal e fertilizing capacity in conjunction with an assisted reproductive pr ogram.