SEPARATE ESTIMATION OF BIOLOGICAL AND ANALYTICAL VARIANCE-COMPONENTS WHEN QUANTITIES AND REAGENTS ARE UNSTABLE

A model for reliable estimation of variance components for biological within-and between-subject variation as well as for analytical variati on when both the quantity and the reagents are unstable has been estab lished. This model was applied to the alpha-interferon receptor on hum an leucocytes which involves two major problems. First, the receptor h as to be quantified within a few hours after blood sampling, and secon d, the reagents for the measurement procedure must be used within 2 we eks. For the number of receptors per cell the biological estimates of coefficients of variation were 14% for within-subject variation and 20 % for between-subject variation, respectively. For the dissociation co nstant both estimates were zero as expected. The model is robust and a pplicable to other systems with unstable quantities and reagents.