Abstract: | After extraction of the sample (on filter paper) in the counting vial, cortisol is assayed by adding 50 microL of horse serum containing tritiated cortisol, and 2 mL of toluene scintillator, shaking for 20 min, and counting the radioactivity in a liquid-scintillation counter at ambient temperature. The method can be applied to saliva, serum, or urine--directly as wet samples or dried on the filter paper. Only inexpensive reagents, which are stable for months to years, are needed. |