Cross-reaction of an anti-Cryptosporidium monoclonal antibody with sporocysts of Monocystis species.

The non-specific cross-reaction of a fluorescently labelled anti-Cryptosporidium monoclonal antibody was observed microscopically when testing faecal specimens from small mammals. The reactive particles were identified as sporocysts of the Gregarine family Monocystidae, and indicate that considerable care should be taken so that false positives are not recorded.