A sensitive polarized fluorometer for clinical tests

A fully automated fluorometer which measures fluorescence depolarization is described. The instrument has been designed to work with standard microtiter sample holders normally used in clinical tests. The combination of a hybrid optical system, built with discrete optical elements and fiber bundles, and a digital Fourier analysis of the detected signals make the instrument quite sensitive and precise. The 96 samples are scanned in about 100 s, with a reproducibility of the measurement of the polarization ratio of about 10-3 and a minimum content of fluorescein in the sample well of 20 pmol