Modified PYNFH Medium is the recommended formulation for the axenic cultivation of small, free-living amoebae, including Hartmannella, Naegleria, Willaertia, Vahlkampfia, Capsaspora, Nuclearia; the trypanosomatids Crithidia, Blastocrithidia, Herpetomonas, Leptomonas, Phytomonas; and certain ciliates such as Tetrahymena, Dexiostoma, and Glaucoma. It is provided freeze-dried, 1 vial prepares 55 mL of medium. The medium is ready to use upon rehydration with sterile glass-distilled water.