YM Broth is used for the cultivation of fungi in a laboratory setting. YM Broth is not intended for use in the diagnosis of disease or other conditions in humans.

YM Broth is prepared according to the formulation published by Wickerham. Wickerham suggested that YM Broth, acidified to pH 3.0 – 4.0, be used as an enrichment medium for yeasts from populations also containing bacteria and molds. To favor isolation of fermentative species, add a layer of sterile paraffin oil 1 cm deep on the surface of the inoculated broth. Cultures should be incubated until growth appears, and then streaked onto YM Agar to obtain isolated yeast colonies. To isolate fermentative and oxidative strains, place acidified inoculated YM Broth on a rotary shaker for 1 to 2 days. This favors yeast recovery while preventing sporulation of molds.

Media selectivity may be enhanced through acidification or addition of selective agents. YM Broth may be acidified prior to sterilization.