A flow cytometric method for rapid selection of novel industrial yeast hybrids

We rapidly produced and isolated novel yeast hybrids by using two-color flow cytometric cell sorting. We labeled one parent strain with a fluorescent green stain and the other parent with a fluorescent orange stain, and hybrids were selected based on their dual orange and green fluorescence. When this technique was applied to the production of hybrids by traditional mating procedures, more than 96% of the isolates were hybrids. When it was applied to rare mating, three hybrids were identified among 50 isolates enriched from a population containing 2 x 10(6) cells. This technology is not dependent on genetic markers and has applications in the development of improved industrial yeast strains.