Applications of a three parameter variance function in statistical analysis of immunoassay data

A three parameter variance function for immunoassay data is described. It can be directly estimated from any replicated data and is therefore suitable for summarizing any variance relationship (within-assay, between-assay, between-laboratory, etc). In general, the variance function has application in any context which requires an estimate of the magnitude and/or structure of errors. Specific applications considered here are: imprecision profile plots, estimation of least detectable concentration and working range, variance stabilizing transformations, weighting functions and bias profiles. Examples given to illustrate these applications are intended to emphasize the utilization of data collected over a period of time from a series of representative routine assays. (author). 12 refs, 5 figs