Computer-assisted analysis of sperm morphology with the aid of lectin staining

Lectins are useful for staining the acrosome, which is a pre-requisite for the assessment of acrosome reaction in vitro. We tested wheat germ agglutinin, peanut agglutinin and pisum sativum agglutinin. The determination of the categories of normal and abnormal spermatozoa as defined by the World Health Organization, including an additional category 'acrosome-less cell', was performed with the aid of a system of computer-assisted semen analysis (CASA) in comparison with visual estimation. The acrosome reaction in vitro was induced by calcium ionophore A23187. Incubation with A23187 decreased the percentage of normal sperm heads and increased the number of acrosome-less sperm heads in comparison with the control samples. This shift was demonstrable with all three lectin staining procedures. No significant differences were observed in the comparison of sperm classes obtained by visual assessment or determination by CASA with two of the lectin staining procedures. After staining with pisum sativum agglutinin the classes of normal and of acrosome-less spermatozoa were significantly different between visual and CASA estimation. Our results indicate that estimation of the acrosomal status in vitro is possible by CASA when lectin staining is used.