Quantitation of leukotaxis in agarose by three different methods.

The agarose method for measuring chemotaxis has been rigorously examined by a variety of quantitative approaches, including measurements of the distance of cell migration ('leading front'), counts of total numbers of migrated cells, and counts of migrated cells in single planes. These methodologies are described in detail. It is demonstrated for the first time that the results are dependent on the concentration of chemotactic factor. Results obtained by the three quantitative methods are similar. Measurement of cells migrating in a single plane is preferable because this method is reliable and relatively simple. The assay conforms to a pattern determined by checkerboard analysis that confirms a true chemotactic response.