Assays for eukaryotic cell chemotaxis.

Chemotaxis is essential for many biological processes. Much of our understanding of the mechanisms underlying chemotaxis is based on a variety of in vitro assays. We review these assays, dividing them into groups depending on the process used to generate the gradient. We describe how each method works, its strengths and limitations, and provide some information about the kinds of cells that have been studied with each assay.