Modification of RPMI 1640 for use in vitro immunological studies of host-parasite interactions in giardiasis.

Incubation of trophozoites for 6 h in RPMI 1640 affected the viability of the parasite; however, RPMI 1640 supplemented with L-cysteine did not affect trophozoite viability, ability to grow when transferred to fresh TYI-S-33, or ability to infect gerbils. Similarly, incubation of murine spleen cells in modified medium did not affect the viability of the cells or proliferative responses to mitogens. RPMI 1640 supplemented with 11.4 mM L-cysteine is a suitable maintenance medium for in vitro studies in immunoparasitology because it maintains viability as well as some of the physiological functions of both trophozoites and lymphocytes.