The synthesis of fluorescent penicilloyl haptens and their use in investigating 'penicillin' antibodies by fluorescence polarization

Adaptation of fluorescence polarization immunoassay to the assay of macromolecules

This paper describes an original methodology for determining macromolecular antigen levels by polarization of fluorescence. it involves the use of fluorescent derivatives of Fab fragments of a monoclonal antibody (Mr 50,000), whose fluorescence polarization rises significantly when it combines with a macromolecular antigen. An experimental system (Fab anti-aldosterone and aldosterone--bovine serum albumin (BSA)) is studied to test this methodology, which was then used to develop an immunoassay for human immunoglobulin M (IgM), using anti-mu chain Fabs. In the two assays, the binding stoichiometry of Fab/antigen was 10/1 and 8/1 for aldosterone--BSA and IgM, respectively. The lower limit of detection of the IgM assay was 0.8 microgram/ml and thus it was applicable to clinical detection of IgM concentrations.

Polarisation fluoroimmunoassay of phenytoin

A polarisation fluoroimmunoassay for the determination of phenytoin levels in serum is described. Fluoresceinthiocarbamyl alpha,alpha-diphenylglycine (FTC-DPG) is used as an easily prepared fluorescent-labelled analogue of phenytoin. Interference from the non-specific binding of FTC-DPG by serum proteins is eliminated by proteolytic degradation of samples prior to assay. The method employs stable, non-radioactive reagents, requires no separation procedure, and involves only 1.25 microliter of serum. Analyses of serum samples from patients receiving phenytoin correlate well (r = 0.96) with an established gas-liquid chromatographic method.