Several culture models exist to study fibroblasts' ability of to reorganize and contract collagen matrices in vitro. In the floating matrix contraction model, a freshly polymerized collagen matrix containing cells is released from the culture dish and allowed to float in culture medium, and contraction occurs in the absence of external mechanical load and without appearance of stress fibers in the cells. The CytoSelect™ 48-Well Cell Contraction Assay Kit provides a simple system to assess cell contractivity in vitro and screen cell contraction mediators using the floating matrix model. The kit's proprietary Cell Contraction Plate eliminates the matrix releasing step of the conventional contraction assay, providing a faster, higher-throughput method to assess cell contraction. Each kit provides sufficient quantities to perform up to 48 assays in a 48-well plate.