Improved Fluorescence Detection Performance With An Avant™ Filter Set

Fluorescence microscopy enables precise localization of biochemical components by detecting fluorescent probes bound within biological tissue, relying on optical filter sets composed of exciter, dichroic, and emitter filters. Traditional filter design has long struggled with small Stokes Shift probes, whose excitation and emission peaks are closely spaced. Standard filters, such as BrightLine®, often fail to capture full emission signals because their critical spectral edges cannot be placed close enough together without risking overlap caused by manufacturing variability.

To overcome this challenge, IDEX Health & Science introduced the Semrock Avant™ filter family in 2021. Avant filters were engineered with three key improvements: tighter control of spectral edge variation, steeper transitions between transmission and blocking, and deeper blocking adjacent to the critical edges. These innovations allow optimal performance when working with probes that have minimal separation between excitation and emission peaks.

In a case study, Alexa Fluor 555 was used to stain fast-twitch myosin isoforms in sheep skeletal muscle tissue. Imaging was performed under controlled conditions using identical microscope hardware, with only the filter sets varied between BrightLine and Avant. Comparative results revealed that Avant filters delivered a 20% increase in average signal intensity in green pseudocolored regions. This improvement matched theoretical predictions generated using IDEX’s SearchLight™ simulation software.

The findings demonstrate that Avant filters significantly enhance imaging performance by capturing more fluorescence signal while reducing noise. This validates the design approach of using sharper edges and tighter manufacturing tolerances for small Stokes Shift probes in biological imaging.