A Chemotactic Assay Enabling Recovery of Cells after Migration

This chapter discusses a chemotactic assay enabling recovery of cells after migration. Chemotaxis determines the direction of cell locomotion using a soluble gradient of a chemical substance. If the chemotactic substance is present in an isotropic unchanging concentration, then cell locomotion is random. Alternatively, if the substance is present in an anisotropic or gradient concentration, the locomotion becomes directed along this gradient. Chemotaxis can be measured using a number of techniques based on different principles. Using an under-agarose assay, the net movements of a population resulting from a chemotactic response are measured, but cells must survive for a long period and must also be able to migrate in agarose. In this assay, thin micropore filters are used; the attracted cells pass through the filter and fall into the lower part of the well. Migrated cells can then be counted, phenotyped, and/or submitted to differentiation experiments.