Trypanosoma brucei: detection of low parasitaemias in mice by a miniature anion-exchanger/centrifugation technique.

A method is described for the detection of trypanosomaemia in mice using the samples of about 55 microliter of blood which can be readily obtained from mice by puncture of the retro-orbital plexus with heparinized glass microhaematocrit tubes. The samples, mixed with an appropriate diluent, are passed through small (2 ml) anion-exchanger columns by means of peristatic pumps and the eluates collected in tubes which can be centrifuged so as to concentrate any organisms in the terminal part of the tube, of calibre about 200 micrometer, for microscopical examination. Evidence is presented to show that the method is more sensitive than other methods in use. It is also quick, requiring only some five minutes per mouse examined.