Estimation of serum gentamicin by quenching fluoroimmunoassay.

Rapid, Simple Enzyme Immunoassay for Gentamicin

“…No sample dilution is involved, as is the case with most immunoassays for gentamicin, such as the radioimmunoassay (4) and fluoroimmunoassay (8,9). Although this does mean that larger amounts of antiserum are needed, one rabbit can produce in 1 year enough antiserum for 100,000 tubes.…”

Fluorescence Immunoassay

“…The reaction mixture was purified on a Sephadex column, with unreacted gentamicin being well separated from the fluorescein-labeled gentamicin. Polarization and quenching immunoassays (uide infra) were performed with the conjugate, and the results were comparable in sensitivity to bioassay and radioimmunoassay (25,26).…”

Fluoroimmunoassay of serum gentamicin

“…When FTC-gentamicin is bound by anti-gentamicin sera from different animals (13 rabbits), a partial quenching of its fluorescence is invariably observed (diagrammatically illustrated in Figure 2) (12). Antibody binding of FTC-gentamicin may therefore be assessed by conventional fluorimetry of unseparated assay mixtures.…”

“…Assay of serum samples by QIA (12) involves addition to one aliquot of prediluted serum sample (for example, 0.5 ml of a I :50 dilution) or standard of an appropriate amount of FTC-gentamicin, followed by antiserum, and to another aliquot an equivalent volume of buffer (this latter serving for estimation of the serum blank). After incubation at room temperature for any convenient period longer than 5 minutes, fluorescence intensities of the assay mixtures and blanks are measured.…”