The fluorescent microscope is the most expensive piece of equipment needed for FISH. The cost is often a roadblock for smaller laboratories. However, a good fluorescent microscope will last many years and is well worth the price of acquiring it.
Fluorescent microscopes usually come equipped with a standard set of filters. The common filters include a DAPI filter (blue), a FITC filter (green), and a Texas red filter. Standard filter sets have broad bandpass excitation and emission filters to obtain the maximum brightness. A detailed description of the differences between wide bandpass and narrow bandpass filters is beyond the scope of this course. However, appropriate filters must be used to score the slide, and the fluorescent dyes in the probes determine the filters. The specification sheet accompanying the probe should contain information regarding the appropriate filter. The manufacturer of the fluorescent scope can assist in selecting the appropriate filters for the particular fluorescence microscope being used.
