ABSTRACT

Cryopreservation is simply a method of keeping living cells frozen with the chance of regaining cellular viability, functions and antigenic structures whenever required, after heating.

In the present study, dimethyl sulphoxide (DMSO) was mixed with the red blood cells having 20% of parasitemia obtained from the mice infected with Plasmodium yoelii and Plasmodium berghei at a fi nal concentration of 15%. For cryopreservation: both test tubes containing each Plasmodium species were kept 10 minutes at room temperature, 30 minutes at +4ºC, 90 minutes at -20ºC and fi nally at -80ºC. Some were left at this temperature, while some were transferred into the liquid nitrogen tank at -196ºC after being left at -80ºC for three hours.

Our observations and assessments demonstrated that both P. yoelii and P. berghei might keep their viability and virulence at -80ºC and -196ºC between the fi rst and the sixth months of cryopreservation.

It can be concluded that the cryopreservation of P. yoelii and P. berghei at -80ºC and -196ºC are successful, indicating the advantage of the establishment of parasite cryobanks in research laboratories.

Keywords: Malaria, Plasmodium yoelii, Plasmodium berghei, cryopreservation