A HIGHLY EFFICIENT IN-VITRO CLONING PROCEDURE FOR ASEXUAL ERYTHROCYTIC FORMS OF THE HUMAN MALARIA PARASITE PLASMODIUM-FALCIPARUM

A very reliable and productive technique for cloning of Plasmodium fal ciparum in vitro is proposed, as demonstrated by successive limiting d ilution of suspensions of asexual extreme importance for a better unde rstanding of the behaviour of the parasite, also in field conditions. The method is rapid, simple and efficient. The growth of the clones wa s individually monitored and the culture conditions were constantly ad justed during their stay in recipients of increasing size. A yield of 18/96 (18.75 %) of provisional clones was obtained, while the superclo ning phase resulted in 16/80 (20 %) positive cultures. The probability that the latter were derived from a single progenitor is very high (9 9 %). It was shown that three randomly selected clones (A1A9, A1B11, a nd A1C10) have excellent growth characteristics before and after cryop reservation, and after a longer period of culture in standard conditio ns.