1. Glycerol-egg yolk citrate, and
2. Test yolk buffer.

Sperms are preserved in the above solutions by freezing at -2 degree'to -10 degreeC and stored in liquid nitrogen at -196 degree C. In this state the sperm can remain viable for years together. Preservation is done in polypropelene containers.

Sperm washing can he done with

1. Hams F-10 solution, and
2. EBSS Earle's balance salt solution.

These contain bicarbonate buffer and are supplemented with albumin. The solutions also contain antibiotics such as streptomycin plus penicillin or gentamycin. The pH is 7.2 - 7.4 and osmolality 280 mmol/litre.