Assay of chemotaxis by a reversible Boyden chamber eliminating cell detachment.

A modified in vitro assay for measuring chemotaxis of leucocytes is presented. A closed chamber is used in preference to an open one thus allowing reversal of the chamber during the incubation. The responding cells which at the time the chamber is turned over are inside the filter, then migrate upwards and are consequently retained on the filter by gravity. This chamber is compared with the conventional type and various parameters are examined using guinea pig eosinophils and other cell types. Loss of cells in the conventional Boyden technique is negligible for rabbit peritoneal neutrophils but is considerable for human and guinea pig neutrophils and eosinophils. This is circumvented by the proposed method; accordingly it allows more accurate quantitation in clinical and experimental work.