The detection of fluorescence light is a powerful and widely used method for the investigation of biological samples. Its sensitivity and selectivity to specific substances and cell constituents are highly dependent on the performance of the optical filters and other components in the light path. Precise alignment of the spectral characteristics to the fluorescent dye and measurement set-up, steep transitions from high blocking to high transmission, broadband high-level blocking, and long-term stability of these optical components are key factors for reliable and conclusive measurement results. Materion Balzers Optics provides customized high-performance optical filters and optical filter sets for high-performance fluorescence microscopes and fluorescence-based instrumentation.