Unknown

The relative affinity of various steroids for glucocorticoid receptors was measured in a whole cell binding assay. Cells were resuspended in incubation medium (RPMI 1640 containing 10% FCS and 50 mM tricine) at a concentration of l0^7/ml. 0.98 ml aliquots were distributed to 12 x 75 glass test tubes containing either 10uL of I0-6M [3H]-dex and 10uL EtOH (uncompeted) or 10uL 10^6 M [3H]-dex and 10 uL of various concentrations of unlabeled steroid (competed) so that in all incubations the final concentration of [3H]-dex was 10^-8 M. Cells were incubated at 37°C for 1 h with frequent shaking after which 3 ml of room temperature. Hanks BSS were added and the cells immediately collected by centrifugation. Ceil pellets were washed three times in 3 ml of Hanks BSS and finally resuspendcd in 1.6 ml of Hanks BSS. One ml of the final cell suspension was added to 10 ml Aquasol and assayed for radioactivity in Beckman LS9000 liquid scintillation counter.