Round cells are often encountered during semen analysis. It is difficult to distinguish immature sperm cells (heads without tails) from white blood cells without specialized stains.
Sperm cells that have not completed maturation may not have a tail. These cells can look alot like white blood cells (WBCs). WBCs are normal components of blood. An elevated concentration of WBCs in a semen analysis suggests the presence of an infection (often prostatitis).
Methods to detect WBCs (by distinguishing these from immature sperm cells) vary. A simple peroxidase stain is able to identify (nonactivated) WBCs since these WBCs contain abundant peroxidase enzyme. WBCs also have a specific immunoreactive region (called the CD 45 antigen) that can be identified with specific (monoclonal) antibodies that attach to this antigenic site.