A new assay for the measurement of the attachment of neutrophils and other cell types to endothelial cells.

A microassay for the detection of cellular adherence to monolayers of cultured human vascular endothelium has been developed that utilises the uptake by cells of the vital stain, Rose Bengal. Changes in the optical density as a result of increased attachment give an accurate measurement of the extent of cellular adherence. The assay utilises small numbers of endothelial cells to obtain confluent monolayers, is rapid (results available within 1.5 h from commencement), allows large numbers of investigations to be performed at the one time, eliminates the requirement for 51chromium or 111indium-labelled cells, and allows a wide variety of cell types including neutrophils, monocytes, eosinophils, lymphocytes and melanoma cells to be studied. Optimal concentrations of cells, fetal calf serum, of incubation and washing media, methods of removal of unattached cells and morphological assessment of the human umbilical vein endothelial cells are detailed. We report here the methodology of this new adherence assay with special reference to neutrophils using a range of stimulators that may regulate their attachment to endothelium.