QXL™ 610 dyes are optimized quenchers for ROX and Texas Red® fluorophores. Their absorption spectra perfectly overlap with the fluorescence spectra of ROX and Texas Red® dyes. This characteristic makes QXL™ 610 dyes excellent quenchers for ROX and Texas Red® fluorophores. QXL™ 610 acid can be coupled to amino groups via EDC-mediated reactions.