Critical evaluation of methylcellulose as an alternative medium in sperm migration tests.

BACKGROUND: The aim of this study was to evaluate the ability of human spermatozoa to penetrate methylcellulose (MC) and to compare this with penetration in hyaluronic acid. METHODS: Spermatozoa from normal (>or=20 x 10(6) sperm/ml, >or=50% progressive motility, >or=5% normal forms) and oligozoospermic (<20 x 10(6) sperm/ml) semen samples were allowed to swim into glass capillary tubes containing methylcellulose with a viscosity of 15 centipoise (cp) (MC15) and 4000 cp (MC4000), hyaluronic acid (rooster comb) or Sperm Select. Penetration of the spermatozoa at 1, 2, 3 and 4 cm were correlated with basic semen parameters (concentration, motility and morphology). The effects of temperature on penetration into MC4000 were explored at 17-37 degrees C. RESULTS: Higher numbers of spermatozoa penetrated MC4000 (10 mg/ml) compared with MC15 and the hyaluronic acid preparations. There was a highly significant correlation between the number of spermatozoa at all migration distances in MC4000 (10 mg/ml) and semen parameters. Increases in temperature from 17-37 degrees C were accompanied by significantly higher numbers of spermatozoa at each penetration distance. MC4000 at 10 mg/ml was at least as favourable to sperm penetration as human cervical mucus. Effective discrimination between normal and abnormal samples was achieved using MC4000 (10 mg/ml). CONCLUSION: Our results suggest the potential use of methylcellulose (MC4000, 10 mg/ml) as a reproducible and effective alternative to hyaluronic acid in sperm migration tests.