The cluster-tray method for rapid measurement of solute fluxes in adherent cultured cells.

Several techniques involving cell suspensions or cells attached to tissue culture dishes or cover slips have been described for measuring the flux of radioactively labeled substrates across the plasma membrane of eukaryotic cells (l-6). All these approaches are time consuming and cumbersome on a large scale. In this report we describe the construction of simple equipment based on the Costar 24-well tissue culture cluster dish to facilitate the measurement of transport in adherent animal cells maintained in tissue culture. The technique is easy to set up, relatively inexpensive, convenient, and allows rapid as well as long-term assays. It has been successfully used in four laboratories’ and with four different cell types (human skin fibroblasts, hepatoma tissue culture cells, Chinese hamster ovary cells, freshly isolated hepatocytes in primary culture). Recently, results obtained using this cluster-tray tech-