The use of collagen or fibrin gels for the assay of XXXX neutrophil chemotaxis.

@entity1 @entity5038 @entity5037
Neutrophil leucocytes are known to migrate actively into 3-dimensional gels of collagen or fibrin. In this paper, we have used such gels to study chemotaxis of @entity1 blood neutrophils towards gradient sources of @entity5037 ( @entity5038 ) using 2 assay systems. The first resembled the micropore filter assay in that neutrophils on the upper surface of collagen gels were allowed to invade in the presence of either an isotropic concentration or a gradient of @entity5038 . Neutrophils invaded the gel vigorously in both cases. The effect of the gradient was assessed by determining the population distribution at different levels in the gel. Cells moving randomly should be distributed normally, and directional locomotion should cause deviation from normal distribution. Such a deviation was seen, but was of marginal significance. A more direct demonstration of chemotaxis was achieved by the second assay in which an agarose slab containing @entity5038 was incorporated into a gel, and the paths of nearby neutrophils were filmed. These cells showed an unequivocal directional response to the @entity5038 gradient. Protein gels can thus be used in the same way as both the presently used filter assays and visual assays using plane substrata, but with the advantage of providing a more physiological environment for the study of chemotaxis than either.
