ABSTRACT

Objective:

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.

Methods:

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.

Results:

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.

Conclusion:

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.