Locomotion through three-dimensional type I rat tail collagen. A modified mini-assay.

There is an increased application of three-dimensional type I rat tail collagen as an in vitro model for the peritumoral matrix in analysis of lymphocyte migration. The increased demand prompted us to modify the previous methods. We here describe our 'mini'-setup of the collagen model assay, which uses only 1/20 the amount of collagen medium and the number of cells used in the conventional assay. The modified assay was tested for optimal collagen concentration in gel for upward and downward migration, for locomotion from a collagen-gel bead into a collagen overlayer for demonstration of the effect of inhibitors and for differentiation between locomotory properties of lymphocyte subpopulations. The results verify that the mini-assay is an applicable in vitro model, easily read and amenable to limited blood samples such as those obtained from cancer patients, and reflects well known in vivo events.