You can frog onto DENSE lawns of the opposite mating type, mate overnight
and frog out or velvet onto selective plates. Mating is inefficient in
dense cultures if they're dense due to extensive growth; stationary phase
cells mate poorly. There's a good high-efficiency mating protocol in a
Rogers and Bussey paper from way back when. It's a reference in Azpiroz
and Butow (1993), Mol. Biol. Cell Vol. 4 p. ? Alternatively, this paper
has a more user-friendly version of the Rogers and Bussey protocol. It is
NOT practical, however, for hundreds of crosses at a time. Good luck.
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Ricardo Azpiroz
Department of Biochemistry
Life Sciences South
University of Arizona
Tucson AZ 85721-0106
azpiroz at U.Arizona.EDU
