Assessing the viability of mutant and manipulated sperm by artificial insemination of Caenorhabditis elegans.

We describe a protocol for artificial insemination of Caenorhabditis elegans which we used to evaluate the viability of sperm from different strains and of sperm activated in vitro. Worms can be artificially inseminated with almost 100% success. Both male and hermaphrodite sperm can be used for insemination. Sperm from a sterile hermaphrodite [fem-3(q23ts)] were found to be viable. As with normal mating, male sperm inseminated into hermaphrodites artificially outcompete the hermaphrodite's own sperm, even though they have not been ejaculated with seminal fluid. Spermatozoa that were activated in vitro from spermatids by the weak base triethanolamine were viable. In contrast, spermatozoa activated in vitro by protease treatment were not.