9522516 Hammer This proposal is on research to use rat basophilic leukemia (RBL) cells to study the relationship between chemical recognition and cell adhesion under hydrodynamic flow. Antigen-coated polyacrylamide gel substrates will be synthesized, and the adhesion of murine immunoglobulin E (lgE)-coated RBL cells to these substrates will be measured in a parallel-plate flow chamber. Adhesion will be measured with optical videomicroscopy. Studies which use multiple lgE-antigen pairs with different properties of chemical recognition will be performed. The effect of adhesion on flow rate, antigen and lgE surface densities, and rate and affinity of chemical binding will be measured. Also, the conditions that promote optimal cell detachment, such as applied hydrodynamic force and soluble antigen competitor concentration, will be determined. In addition, and advanced form of flow chamber and a computer simulation method will be developed. ***