This Hidip slide is recommended for cultivation of wide variety of microorganisms and heterotrophic plate count to treated portable water using longer incubation periods. TSA/SCDA as a general purpose growth medium used for the cultivation of wide variety of microorganisms including bacteria and fungi. Tryptone and Soya peptone supplies the essential nutrients. R2A Agar : This medium is recommended for detection of heterotrophic plate count of treated potable water using longer incubation periods.