The fluorescent microscope is the most expensive piece of equipment needed for FISH. The cost is often a road block for smaller laboratories. However, a good fluorescent microscope will last many years and is well worth the cost of acquiring it. Several brands are available.
Fluorescent microscopes usually come equipped with a standard set of filters. The common filters include: DAPI filter (blue), FITC filter (green), and a Texas red filter. Standard filter sets have wide bandpass excitation and emission filters to obtain the maximum brightness. A detailed description of the differences in 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 filters are determined by the fluorescent dyes in the probes. The specification sheet that accompanies the probe should contain information regarding the appropriate filter to use. The manufacturer of the fluorescent scope can assist in selection of the appropriate filters for the particular fluorescence microscope being used.