Automated in-line ratio-correcting filter fluorometer.
We have developed a novel optical arrangement for the Abbott VP bichromatic analyzer, converting it into a fluorometer upon insertion of a specially designed filter carriage. Fluorescence intensity is measured by using straight-through excitation geometry and is corrected for fluctuations in light-source intensity by using the attenuated transmitted beam through the solution as a reference. The modification allows switching from the absorbance to fluorescence mode without an auxiliary light source or a major hardware change. The detection limit for an experimental prototype was estimated as 192 pmol of fluorescein per liter. In an application to a fluorescence immunoassay for theophylline in patients' sera, the data (y) correlated well with results by an enzyme immunoassay procedure (EMIT), giving a correlation equation of y = 1.849 + 0.988x (r = 0.969). A fluorometric standard curve for glucose and some performance data are also presented.
D005374:Filtration / Q000295:instrumentation; D005452:Fluoresceins; D005470:Fluorometry / Q000295:instrumentation*; D005947:Glucose / Q000032:analysis; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008962:Models, Theoretical; D013806:Theophylline / Q000097:blood
D005452:Fluoresceins; D013806:Theophylline; D005947:Glucose