ReadiUse™ DXAQ7 Staining Solution is a far-red fluorescent anthraquinone dye designed for selective nuclear staining of non-viable and permeabilized cells. Its membrane-impermeable properties prevent uptake by intact cells, making it an effective tool for the exclusion of non-viable cells in flow cytometry. ReadiUse™ DXAQ7 exhibits a high binding affinity for double-stranded DNA (dsDNA), intercalating rapidly to facilitate accurate quantification of DNA content in fixed-cell cycle analysis. Notably, it provides twice the fluorescence intensity of DRAQ7™ (Thermo Fisher), enhancing sensitivity and signal resolution for improved detection in various analytical platforms. In fluorescence microscopy, it functions as a robust nuclear counterstain and a reliable viability indicator in endpoint assays, with low cytotoxicity that supports extended cell culture studies.

ReadiUse™ DXAQ7 exhibits a broad excitation range from 488 nm to 647 nm, with optimal excitation achieved using red laser lines. Upon binding to dsDNA, it emits at a peak wavelength of 697 nm, providing a high signal-to-noise ratio for precise detection. In flow cytometry, the dye can be efficiently detected using PerCP-Cy™ 5.5 or PerCP-iFluor® 710 filter sets when excited by a blue laser, while BP or LP filters optimized for Cy5 detection are recommended for red laser excitation. For fluorescence microscopy, the dye is optimally excited with yellow to red light sources and detected using far-red longpass filters such as 695LP, 715LP, or 780LP.

ReadiUse™ DXAQ7 does not require UV excitation, allowing compatibility with FITC and PE fluorophores without spectral compensation. However, due to its broad excitation spectrum and far-red emission, it is not recommended for use with other far-red fluorophores excited by blue-to-red light.