DAPI wavelength is a critical aspect in fluorescence microscopy, particularly for staining DNA in cell nuclei. DAPI (4',6-diamidino-2-phenylindole) is a fluorescent stain that binds strongly to adenine-thymine-rich regions in DNA. When excited by ultraviolet light, DAPI emits blue fluorescence, making it highly valuable for visualizing cell structures in research. https://optolongfilter.com/products/dapi-excitation-emission-filter/