Although DABCYL is one of the most popular acceptors for developing FRET-based nucleic acid probes and protease substrates, its extremely high hydrophobicity and resultant poor water solubility have limited its use in the development of sensitive fluorogenic FRET probes. DABCYL Plus™ is developed to address this limitation. DABCYL Plus™ retains spectral properties similar to those of DABCYL. This feature enables researchers to keep all assay settings similar to those of DABCYL’s probes. In addition, DABCYL Plus™ has much greater water solubility than DABCYL. We have used DABCYL Plus™ to develop various protease substrates. In some cases, it has demonstrated greatly improved enzyme performance.