DY5945-DY8531 cross
CBS5557-derived h+ strain DY5945 was crossed with an h- laboratory strain clone DY8531. Random spores were germinated on YES plates to form colonies. To score the maltose utilization phenotype, the colonies were inoculated into 96-well microplates containing either glucose-containing medium or maltose-containing medium. After incubating at 30ºC for 24 h, the extent of growth in each well was determined by visual inspection. The progenies that grew in both types of media were deemed Mal+, whereas the progenies that only grew in glucose-containing medium were deemed Mal-. The Mal+ progenies were pooled in equal amounts to form the Mal+ pool, and the Mal- progenies were pooled in equal amounts to form the Mal- pool.