COMPUTERIZED MICROASSAY OF KERATINOCYTE CELL-PLASTIC ATTACHMENT AND PROLIFERATION FOR ASSESSING NET STIMULATORY, INHIBITORY AND TOXIC EFFECTS OF COMPOUNDS ON NONIMMORTALIZED CELL-LINES

Testing of pharmacological agents that affect growth of epidermal kera tinocytes (EK) requires a standardized assay. We have developed an ass ay measuring net effects of stimulatory (e.g. growth factors), inhibit ory (e.g. methotrexate) or toxic (e.g. Triton X-100) compounds. The am ount of crystal violet staining viable EK attached to the wells of sta ndard 96-well microplates is measured in situ using an ELISA plate rea der. Optical density readings are directly converted into cell counts by computer software. Counts obtained by this method strongly correlat e with the results obtained using the H-3!thymidine uptake assay and direct cell counts. The assay standardizes measurements of nonimmortal ized EK lines with different innate proliferative properties and allow s accurate quantitation of EK numbers in the range of 2,500-500,000 EK /well.