Sperm immobilization test and quantitative sperm immobilization test using frozen‐thawed sperm preparation applied with computer‐aided sperm analysis

Abstract

Purpose In a previous study, a new method was described using the sperm immobilization test (SIT) with computer‐aided sperm analysis (CASA). However, obtaining high‐quality sperm as needed was a known issue. Here, we compared the results of using frozen‐thawed sperm and fresh sperm for the SIT using the CASA method. Methods For the frozen‐thawed preparation, 500 μL of condensed semen and 500 μL of Sperm Freeze were mixed in a cryovial and cryopreserved in liquid nitrogen. Density gradient centrifugation was used for the collection of motile sperm in both the fresh and frozen‐thawed sperm preparations. A total of 50 serum samples were prepared for both the fresh and frozen‐thawed sperm with each sample tested containing 10 μL of serum, 1 μL of either fresh or frozen motile sperm suspension, and 2 μL of complement. Sperm motilities were measured using CASA after a 1‐hour incubation period for both fresh and frozen‐thawed sperm. Results Both fresh and frozen‐thawed sperm reacted similarly when exposed to serum containing sperm‐immobilizing antibodies asserting the use of frozen‐thawed sperm for the diagnosis of immunological infertility. Conclusion These results suggest the possibility of using cryopreserved sperm for the SIT when fresh sperm is unavailable.