Plates are sample-ready, eliminating the time-consuming, cumbersome step of preparing media/agar dishes. This plate has been awarded Official Methods of Analysis (OMA) #997.02. 3M Petrifilm plates use 75% less energy, use 79% less water, produce 75% less greenhouse gases and result in 66% less waste (by weight and volume) compared to competitive agar methods.Yeasts are typically indicated by small, blue-green colonies with defined edges and no foci. Molds are indicated by large, variably-colored colonies with diffuse edges and center foci.