Steroid receptor analysis by size-exclusion liquid chromatography: considerations for the clinical laboratory

Steroid receptor activity can be more quickly estimated by size-exclusion chromatography than by conventional analysis on sucrose gradients, and profiles of receptor activity are better resolved. Here we discuss several factors affecting this form of analysis in clinical laboratories. The composition of the elution buffer influences steroid receptor elution and recovery: high ionic strength, neutral pH, and the presence of dimethylformamide are important. Of the TSK-SW (Beckman) size-exclusion chromatographic columns we considered, the TSK-G2000SW column appeared to be the most appropriate. "Reference" elution profiles are presented for several marker proteins and estrogen receptor forms generated under different sample-treatment conditions. In examining the sensitivity of receptor analyses by this method, we used fresh rodent preparations, a commercial receptor reference (Estrocept), and human tumor material obtained by needle biopsy. We also compared frozen and lyophilized receptor preparations with fresh ones.