Fig. 1.

Type I collagenase facilitated the release of spermatozoa from colloid semen without affecting sperm morphology and viability. a Chimpanzee semen formed colloid structure, exhibited high viscosity. b 2.4-fold increase in sperm concentration per ml was achieved, and approximately 2.7-fold more spermatozoa in number were collected when type I collagenase was used. c No significant differences were detected on sperm abnormality or sperm viability between control and collagenase-treated groups; W/O: without; MTT: 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide. At least 200 sperm cells were evaluated in each sample. Data were analyzed from 16 ejaculates from 4 individuals