Comparison of Glycerol and a Zwitter Ion Buffer System as Cryoprotective Media for Human Spermatozoa

Abstract

This study compared the cryoprotective effect of glycerol with that of a zwitter ion buffer system (TESTCY). Spermatozoa that are cryopreserved in the presence of glycerol possess a somewhat higher progressive motility immediately after thawing than those preserved in the presence of TESTCY. However, after a 1-hour incubation in glycerol-free medium, the progressive motilities of the glycerol- and TESTCY-treated spermatozoa become essentially identical. After 2 hours in culture medium, TESTCY-treated spermatozoa possess a higher motility than glycerol-treated spermatozoa, indicating that TESTCY is a better preservative than glycerol for the long-term motility of human spermatozoa. The fertilizing potential of the cryopreserved spermatozoa was assessed by their ability to penetrate zona-free hamster oocytes in vitro. Spermatozoa that are cryopreserved in the presence of TESTCY produce three- to four-fold higher penetration rates than glycerol-treated, cryopreserved spermatozoa. Cryopreservation in the presence of TESTCY also results in a higher stability of the acrosin/proacrosin system than when the spermatozoa are preserved in glycerol, since about two- to three-fold higher levels of proacrosin are retained. These results indicate that TESTCY is a better cryopreservative for human spermatozoa than glycerol.

Survival of Human Sperm Following Controlled- and Noncontrolled-Rate Cryopreservation/Die Überlebensrate menschlicher Spermatozoen nach einer kontrollierten und nicht kontrollierten Kryokonservierung

“…Previous studies have suggested that an interaction may exist between rate of semen freezing and level of glycerol supplementation on cryosurvival of human sperm (Jeyendran et al -1984;. From Figures 1-4 it can be observed that sperm cryosurvival following CR compared with NCR freezing was not dependent on level of glycerol supplementation.…”

“…Previous studies having suggested that the optimal concentration of glycerol for freezing human semen may be dependent on the rate of semen freezing (Jeyendran et al -1984;. The final objective of this study was to examine if the optimal concentration of glycerol for freezing human semen differed for the CR and NCR methods.…”

Precision, reliability and biological variability in human sperm function measured by penetration of zona‐free hamster oocytes

“…Two different cryopreservation media, TESTCY (Jeyendran et al 1984) and glycerol, were found to be suitable in about 33% of all our attempts at freezing semen, and in Over half of our most recent attempts. Semen was made 50% with TESTCY, or 10% with glycerol, over a 10-15 rnin period at room temperature, with gentle mixing.…”

Cryopreservation of human sperm in a lecithin-supplemented freezing medium

“…The basic freezing media consisted of a zwitter ion buffer system (TEST) (8). To summarize briefly, the samples were prepared by titrating a 325-mOsm aqueous solution of N-Tris (hydroxymethyl) methyl 2-amino ethane sulfonic acid (CalBiochem, San Diego, CA) with a 325-mOsm aqueous solution of Tris (hydroxymethyl) amino methane (CalBiochem, San Diego, CA) to pH 7.5.…”