Optical Filter Sets For Two Or Three-Colour Fluorescence Detection
F. L. Battye
The Walter & Eliza Hall Institute
A system of optical filtering has been developed for detection of the fluorochromes most commonly used in flow cytometry. Measurement of the fluorescence and background light transmissions has enabled a selection from among stock optical filters of an optimal combination for use in simultaneous detection of Fluorescein and Rhodamine or Phycoerythrin together with Hoechst DNA stain or high angle visible light scatter. The use of logarithmic amplifiers has simplified the measurements and has also allowed separate determination of the optical and electronic background in order to arrive at an optimal operating laser power. An important finding is that the optimal filter in each case is not necessarily the one passing the widest wavelength range.