Nanoparticles coated with lectins and antibodies showing high affinity to cell surface determinants of defective spermatozoa were prepared for experiments amied at the depletion of defective spermatozoa from freshly collected semen for field AI trials or at the depletion of defective spermatozoa from forzen thawed semen for laboratory analyzes and in vitro fertilizaiotn (IVF)