Chemoattractant production by synovial fluid cells in chronic arthritis. A study with a new double-chamber method for quantitating the motility of mononuclear cells labelled with chromium-51.

A new method was developed to study the migration of lymphocytes under in vitro conditions. Attractant fluid was added to the appropriate lower wells, which were filled to the brim. Peripheral blood mononuclear cells were labelled with 51Cr and then put into the upper wells. Surface tension and capillary force are enough to make clamping of these plates possible, separated by a polycarbonate filter, 15 microns thick with a pore size of 8 microns, between these two standard multiwell microculture plates. After three hours of incubation at +37 degrees C in a humidified 5% CO2 atmosphere, the migrated cells were harvested from the lower wells using a semiautomatic harvester, and the radioactivity was counted. The present method makes it unnecessary to enrich or select for different cell subsets for migration studies. Instead, density gradient separated mononuclear cells as such can be used to assess their migratory capacity.