[Cryopreservation of plasmodia with malaria models and establishment of a cryobank].

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 final concentration of 15%. For cryopreservation: both test tubes containing each Plasmodium species were kept 10 minutes at room temperature, 30 minutes at +4°C, 90 minutes at -20°C and finally at -80°C. Some were left at this temperature, while some were transferred into the liquid nitrogen tank at -196°C after being left at -80°C for three hours.

Results: Our observations and assessments demonstrated that both P. yoelii and P. berghei might keep their viability and virulence at -80°C and -196°C between the first and the sixth months of cryopreservation.

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