Cryopreservation of Blastocystis hominis with Dimethylsulphoxide (DMSO)

Abstract

Very few cryopreservation studies have been carried out on the protozoan parasite, Blastocystis hominis. The present study compares the cryoprotective ability of two cryoprotectants, mannitol in glycerol with and without dimethylsulphoxide (DMSO). The study also aims at selecting a good growth medium with appropriate supplement which can support cryopreserved parasites and to determine the minimum number of parasites needed for successful cryopreservation. The study showed that the cryoprotectant using DMSO in mannitol and glycerol had better cryoprotective ability. The initial culture medium using lscoves Minimum Dulbecco's medium (IMDM) should have 20% horse serum as nutrient supplement in order to resuscitate cryopreserved parasites. The critical concentration for cryopreservation of parasites should exceed 200 x 106 parasites per ml in order to obtain a good recovery of parasite in culture after cryopreservation.