Plasma Cortisol (PCS1)
Blood samples for measurement of plasma cortisol were obtained on two occasions, 1 and 2 weeks prior to viral challenge, respectively. Samples were collected under resting conditions, such that subjects had sat quietly for a 30-min adaptation period before blood was drawn.
Plasma cortisol was measured using a double-antibody competitive radioimmunoassay. Cortisol concentrations measured during each of the two assessments were correlated .70, p<.001.
Ruder, H. J., Guy, R. L., Lipsett, M. B. (1972). A radioimmunoassay for cortisol in plasma and urine. The Journal of Clinical Endocrinology & Metabolism, 35, 219-224.