Development of A High Throughput Cell Migration Assay Using the Sru Bind Reader

Abstract The chemotactic ability of non-adherent cells can be assessed by a variety of techniques, but is typically performed using transwell plates in which a chemoattractant induces the migration of cells through a porous membrane. Throughput and robustness are limitations to this assay format. The aim of this study was to develop a novel, higher throughput, robust, cell migration assay using the human monocytic derived U937 cell line and the SRU BIND® label free detection platform. C5a is a powerful chemoattractant which is generated by all 3 pathways of the complement system. C5a binds to the C5a receptor which is expressed on many different inflammatory cell types, including neutrophils, monocytes, and macrophages, and it mediates migration of these cells under pro-inflammatory conditions. Differentiated U937 cells express the C5a receptor and migration of these cells can be induced by C5a. These cells were seeded on a 384-well BIND® biosensor and following an attachment period, collagen was added and allowed to form a solidified layer. Following the addition of C5a the cells migrated up off the biosensor toward the chemoattractant stimulus producing a bell shaped concentration response curve, as typically observed for C5a in classical chemotaxis assays. The response was inhibited by reference C5a receptor antagonists. This assay format could also be developed to evaluate the migratory ability of primary cells such as monocytes or neutrophils to inflammatory chemoattractants.