Transmigration of cells through the endothelial cell layer of blood vessels to the underlying tissue is an important physiological pro- cess in inflammation and metastasis. Study of the cell adhesion pro- cess is often conducted in flow cells to emulate the shear found in blood vessels. Here, we describe a microfluidi parallel flow cell system, the BioFlux TM 200, designed to enable the preparation and study of multiple shear flow conditions simultaneously. To test the device, we investigated the adhesion of colon carcinoma cells to en- dothelial cells grown in microfluidic channels under physiological shear flow. Conditions tested were stimulation with IL-1 and adhe- sion blockade with anti-VCAM and anti-E-selectin under variable shear forces. In agreement with the literature (Giavazzi et al. 1993), IL-1 stimulation was found to be a strong mediator of Jurkat cell at- tachment. Anti- VCAM blocked rolling and adhesion of control cells, lymphocytes, to the endothelial surface, but not rolling and adhe- sion of colon carcinoma cells. Anti-E-selectin blocked rolling and adhesion of colon carcinoma cells. The chief advantages of the Bio- Flux 200 system over traditional flow cells were tight and rapid shear control, the ability to maintain experimental integrity by uti- lizing and querying identical conditions in 24 flow cells concur- rently, minimal reagent use, and integrated rolling and adhesion analysis in the software. Future modifications to the system will in- clude further expansion of throughput to a 96-well microtiter plate footprint.