Analysis of steroids in songbird plasma and brain by coupling solid phase extraction to radioimmunoassay.

摘要: It is a common practice to extract steroids from plasma, serum, or tissue samples prior steroid measurement by radioimmunoassay (RIA) enzyme immunoassay (EIA). Steroid extraction critical because it can remove substances that interfere with the RIA EIA. commonly achieved using organic solvents, such as diethyl ether dichloromethane. However, solvent extractions suffer low recovery, imprecise incomplete removal of assay interference. Here, we describe validations simple protocol (e.g., dehydroepiandrosterone, corticosterone, and estradiol) avian brain solid phase (SPE) commercially available C18 columns. We compare various methods for (1) eluting columns, (2) drying eluates, (3) resuspending dried eluates RIA. The SPE method yields high consistent recoveries. also effectively separates interfering substances, even when extracting lipid-rich plasma tissue. These data indicate superior on several measures. should be broadly useful samples.