Determination of parallelism and nonparallelism in bioassay dilution curves
J.Clin.Microbiol., 32 (10):
2441-2447 (1994)Abstract
There is a lack of consensus among investigators who use a variety of immunoassay techniques (e.g., enzyme-linked immunosorbent assay ELISA and radioimmunoassay) regarding the protocols for describing and forming standard reference or calibration curves and interpolating serum antibody concentrations. This confounds the issue of detecting the presence or absence of parallelism between standard reference serum and serially diluted serum sample curves. These curves must be parallel to support the assumption that the antibody-binding characteristics are similar enough to allow the determination of antibody levels in the diluted serum sample. There is no universal and widely adopted strategy for assessing parallelism in bioassays, and without an assurance of parallelism, investigators are not able to calculate reliable estimates for antibody concentrations in serum samples. Furthermore, single-point (dilution) serum assays do not provide information related to parallelism and nonparallel