Western blot analysis of microneme protein binding to HFF cells. Microneme proteins were added to HFF cells at 128C for 1h. Proteins remaining in the supernatant (SUP) were removed, and the monolayers were washed (W1 and W4 correspond to the ®rst and fourth washes respectively). MIC2 bound to HFF cells and was recovered in the cell-bound fraction (CBF) from the puri®ed microneme preparation (microneme prep.) but not from ESA (excretory secretory antigens). In contrast, the dense granule protein GRA1 did not bind to HFF cells, as shown by its absence in the CBF fractions. Dilution standards representing 1%, 5% and 10% of the ESA input material were loaded in parallel (input). Loading of the CBF lane represents 20% of the total recovered material. Blots were probed with a mixture of monoclonal antibody Tg17-43 to detect GRA1 and monoclonal antibody 6D10 to detect MIC2, followed by secondary antibodies conjugated to HRP.