Engulfment of foreign particles by phagocytes is initiated by the engagement of phagocytic
receptors. We have previously reported that NimC1 is involved in the phagocytosis
of bacteria in Drosophila melanogaster. We have identified a family of genes, the
Nimrod gene superfamily, encoding characteristic NIM domain containing structural
homologues of NimC1. In this work we studied the bacterium-binding properties of the
Nimrod proteins by using a novel immunofluorescencebased flow cytometric assay. This
method proved to be highly reproducible and suitable for investigations of the bacteriumbinding
capacities of putative phagocytosis receptors. We found that NimC1, NimA, NimB1 and
NimB2 bind bacteria significantly but differently. In this respect they are similar
to other NIM domain containing receptors Eater and Draper.