xtraFluor™ Violet 420 (XV420) is an extremely bright violet laser-excitable fluorescent labeling dye designed for flow cytometry applications requiring strong violet-channel fluorescence. With excitation and emission maxima near 405 nm and 420 nm, respectively, XV420 is well matched for instruments equipped with a 405 nm violet laser and appropriate detection filters. XV420 can be used as an alternative to BD Horizon Brilliant™ Violet 421 (BV421) and provides brighter fluorescence signal than Pacific Blue™ and BD Horizon™ V450 in violet laser-based workflows. The dye supports improved resolution of dim cell populations and is suitable for multicolor and spectral flow cytometry panel design.

XV420 offers favorable spectral compatibility, fluorescence stability, and workflow compatibility for a variety of flow cytometry applications. The dye can be conjugated to antibodies using Buccutite™ chemistry developed by AAT Bioquest. Compared to conventional SMCC-based conjugation workflows, Buccutite™ chemistry enables antibody labeling under mild conditions such as room temperature and neutral pH without requiring multistep thiol reduction procedures. The resulting conjugates are suitable for flow cytometry applications requiring stable fluorescence signal and efficient violet laser excitation.