Cell-substrate adhesion assays.

In the intact organism, cells adhere to a variety of substrates. It is possible to investigate the nature of the molecules to which cells adhere in two different assays. In the first protocol presented in this unit, physical adhesion of a cell is assessed by determining the extent to which the cell spreads on a defined substrate--the plate is coated with the test substance, cells are added and allowed time to attach and spread, and the extent of spreading is assessed using phase contrast microscopy. In a second assay, an aliquot of cells is added to the well of a microtiter plate coated with a test adhesion molecule and the cells are allowed to attach. Nonattached cells are removed, and the percent of added cells attached to the substrate is quantified by crystal violet staining.