This proposal is for funds to purchase a new fluorescence- activated cell sorter for a multiuser facility in the Biology Division at Caltech. The sorter will be employed in a variety of projects, including sorting of immature cells for developmental lineage analysis, selection of mutant cells and transfectants, quantitation of cell-surface receptor expression in structure- function analysis, and multiparameter phenotypic analysis. Other applications include determination of cell cycle parameters in studies of cell cycle-linked gene expression. The facility currently operates a 1981 Ortho Sorter, which is overbooked, technically inadequate for many current applications, and no longer supported by the manufacturer's service representatives. The lack of a state-of-the-art sorter has become a sever bottleneck for many projects in the division.
