Fig. 3.

Promastigotes of L. donovani incubated with sand fly midguts dissected at different times post-blood meal and various controls. Leishmania donovani promastigotes (24 h after the releasing from macrophages) were incubated in a microtiter plate for 2 h with: a midguts of P. argentipes, P. orientalis, P. papatasi and S. schwetzi dissected at 6, 24, 32, 48 and 72 h post-blood meal; or b with saline, proteinase K (PK), rabbit blood, red cells of rabbit blood, human haemoglobin, blood + proteinase K, red cells + proteinase K and human haemoglobin + proteinase K. As a positive control, parasites killed by 1% formaldehyde and permeabilised by 0.5% Triton X-100 were used