To assess motility and estimate sperm concentration, switch to 400X magnification. An estimate of sperm concentration may be needed to determine an appropriate dilution for the performance of the sperm count. Non-spermatozoa cells, such as epithelial cells (derived from the urogenital tract) and round cells, including leukocytes and spermatids, can be observed using 400X magnification. However, identification and differentiation of leukocytes and spermatids should not be attempted on an unstained wet preparation. These cells can be more accurately identified using PAP- or Wright-stained smears.
A phase-contrast microscope is recommended for wet mount examination of semen.