Abstract:
The objectives of this study were to determine the effect of cryoprotectants and sperm
density for a long-term storage of S. olivacea spermatozoa. Spermatozoa were
obtained by homogenized the spermatophores by a glass homogenizer in an ice-bath
and centrifugation at 4 ° C. Spermatozoa were suspended in calcium-free saline (Ca-F
saline) containing the cryoprotectants glycerol, dimethyl sulfoxide (DMSO) and
methanol at concentration of 5%. Sperm which were vibrated and rotated was counted
as live in sperm viability assessment. Samples of spermatozoa were cooled to -196 ° C
by two-step freezing, first to -80 ° C and then by plunging in liquid nitrogen (LN).
Gradual cooling (1 ° C min-
1
) was done by cooling the spermatozoa. Thawing was
done at 30 ° C water bath for 2 min. This yielded live sperm after storage in LN for 30
days. The best sperm viability was obtained from density of 10
8
cells per ml in
DMSO. There is no significant different (P > 0.05) between cryoprotectant toward
sperm viability. However, there is a significant different (P < 0.05) between density
toward the sperm viability.
