Comparision of Cryosurvival Rate of Human Spermatozoa in Cryopreservation Using a Mechanical and Computerized Freezers

Abstract

Objective To compare the survival rate of human spermatozoa in cryopreservation using two programmed cooling freezers, which have different cooling rates.

Main Outcome Measures The sperm survival rates using two types of freezers were compared. A computer-assisted semen analyser (CASA) was employed to assess sperm motility.

Results The sperm survival rate was significantly higher when using a computerized freezer comparing to the mechanical freezer (paired t-test = 6.95; df = 139; P = 0.05). Using similar method of freezing cryosurvival rate of each group of semen samples showed no significant difference when the results were compared (computer-freezer: t=0.21; P=0.827 with mechanical freezer: t=0.39; P=0.691).

Conclusion Cooling rate used in human sperm freezing is thus an important factor in determining sperm survival in cryopreservation.