AIDS F O R THE ANALYST Fluorescence Measurements with the Beckman Model DU Spectrophotometer. John S. McAnally, Department of Biochemistry. School of Medicine, University of Miami, Coral Gables, Fla.
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for the pure estrogenic compounds agree with those found previously (4). The sensitivity of the instrument lies in the same range as that of other fluorescence meters (Table I). Excib ing light for quantitative measurements with estrone was tiltered through a Bausch & Lomh interference filter with a maximum transmittance at 455 mp and a half baud width of 9 ma. The slit width was 0.3 mm. with an effective band width of 4.7 mp. This instrument modification waa designed for use in estrogen determinations in this laboratory. The proper filters for measuring the fluorescence of other fluorescent substances mere not available. As a consequence, the sensitivity of the instrument for other campounds has not been determined.
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methods have been devised for using the Beckman Model DU spectrophotometer for specidilized fluorescence measurements (8, 4,5, 6). The modification developed in this laboratory (Figure 1) makes possible the determination of fluaresoence spectra and, in addition, the quantitative measurement of various fluorescent compounds in solut,ion. ARIOUS
APP.4RATUS AND PROCEDURE
The light source, which is placed externally, is a Bausch & Lomh No. 42-4442-48 illuminator. This unit contains an 18amwre, 6-volt incandescent bulb with a coil filament. It is ~~~~~~~~
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rescence. Measurements &e; practieahle &a when the 1PZ8 photomultiplier attachment or some equally sensitive currentmagnifying device is available.
ACKNOWLEDGMENT
The author is indebted to Estelle R. Hausman for technical assistance in Figure2. sample carrying out this project. The lamp Holder for Fluohousing used in constructing the appareseenee Measratuswas obtained through the courtesy urements of the Fisher Scientific Co. Thanks are due Erwin Schnrenk, Schering C o p , Bloomfield, N. J., for the estrone. This compound vas obtained by the author from R. T. Hill, School of Medicine, University of Miami. Table I. F i e r e 1. Fluorescence I t t aehment for Recl
