The Sperm-Chex and Sperm-Chex Post VC controls from Streck, Omaha, Neb, are now assayed for use on the Makler counting chamber. The Makler counting chamber device is used for fast and accurate sperm counting, motility evaluation, and cell morphology analysis of a semen fluid sample. With stabilized sperm cells, Sperm-Chex has two clinically significant levels of control to simulate the sperm cell concentration that technologists encounter in patient samples. It has the same chamber loading and optical characteristics as a patient sample. Sperm-Chex verifies the sperm analysis process and tests the technologist’s proficiency in sperm cell quantification and qualification. Sperm-Chex Post VC, with stabilized sperm cells, is a positive/negative post-vasectomy sperm count control with the same chamber loading and optical characteristics as a patient sample. Sperm-Chex Post VC validates the post-vasectomy sperm count procedure. The products are stable for 42 days open-vial and 12 months closed-vial when stored at 2°C to 10°C. For more information, visit Streck.