Staurosporine impairs microneme secretion and parasite invasion equally. A. Staurosporine speci®cally inhibited microneme secretion, but not dense granule secretion. Parasites were treated with 0±5mM staurosporine and assayed for microneme or dense granule secretion by Western blotting culture supernatants with antibodies to MIC2 or GRA1 respectively. B. Staurosporine inhibited microneme secretion and parasite invasion equally. Microneme secretion from staurosporine-treated parasites was measured by quantitative Western blotting. Values are the means of three independent experiments, each with triplicate samples. Staurosporine-treated parasites were assayed for invasion of HFF cells by counting under microscope the mean number of parasites/host cell ($100 host cells counted/ experiment in three independent experiments) after IF staining. C. Staurosporine inhibits parasite attachment to ®xed HFF cells. Attachments of strain 2F (b-Gal) parasites to formaldehyde-®xed HFF monolayers was determined by measuring b-Gal activity. Values are the means6SE of three independent experiments, each with triplicate samples.