Originally designed for Comparative Genomic Hybridization the filter sets in this series, like those in the 51 and 61 series have become important in a wide variety of applications. The factors common to each of the 80 series filter sets is the use of a multiband beamsplitter and emission filter combination which remain stable in the body of the fluorescence microscope. The use of a stable beamsplitter and emission filter guarantees registration of the various images. The single, and sometimes multi-band excitation filters are mounted in a filter wheel or a filter slider. By changing excitation filters one seeks to excite each fluorochrome in succession, capturing a single image and combining those images with the help of imaging software. There can be some bleeding of one fluorochrome into the image of a shorter wavelength fluorochrome. This is sometimes inevitable, as is the case with Propidium Iodide and FITC.