This filter set is ideal for use with TRITC and a number of Rhodamine dyes, as well as other orange fluorophores. This improved set offers the high brightness that has made Semrock famous, and yet with its narrow exciter filter, it also provides a high signal-to-noise ratio and minimizes the bleedthrough in co-labeling applications that is associated with shorter-wavelength yellow and green fluorescent markers, like yellow fluorescent protein (YFP), green fluorescent protein (GFP), and FITC. Note that the narrow excitation filter efficiently captures the 546 nm emission line of mercury or metal-halide-mercury arc lamps.