and then to incubate overnight at room temperature; with this method, gpb-1 produced 100% dead embryos and unc-22 produced 99% Uncs. To further test this new induction method, we fed two more genes, par-1 and par-3, mutations in either gene result in embryonic lethality [8,9]. Using our optimized induction conditions, feeding par-1 and par-3 resulted in 100% and 96% dead embryos, respectively, similar to the results obtained with null mutants (Table 1).