Abstract: Compositions and methods are provided that reduce the time required for detection of botulinum neurotoxins in cell-based assays. In one aspect an isoquinolynyl compound can be used for this purpose. In such cell-based assays the cell can include an enzyme that facilitates degradation of the reporter significantly faster after the cleavage than before the cleavage, and presence of the Botulinum toxin correlates with reduction of the signal from a baseline signal. The cell can advantageously express both the construct that includes the reporter, and an enzyme that facilitates the degradation.

Abstract: Compositions and methods are provided that improve detection of botulinum neurotoxins in cell-based assays. In one aspect an isoquinolynyl compound can be used to enhance the sensitivity of both Förster resonance energy transfer (FRET) and non-FRET cell-based assays. Osmolarity of the cell culture media can be adjusted to optimize the effect of the compound. In that subject matter an environment cell can include an enzyme that facilitates degradation of the reporter significantly faster after the cleavage than before the cleavage, and presence of the Botulinum toxin correlates with reduction of the signal from a baseline signal. Where the environment is a cell, the cell can advantageously express both the construct that includes the reporter, and an enzyme that facilitates the degradation.

Abstract: Compositions and methods are provided that reduce the time required for detection of botulinum neurotoxins in cell-based assays. In one aspect an isoquinolynyl compound can be used for this purpose. In such cell-based assays the cell can include an enzyme that facilitates degradation of the reporter significantly faster after the cleavage than before the cleavage, and presence of the Botulinum toxin correlates with reduction of the signal from a baseline signal. The cell can advantageously express both the construct that includes the reporter, and an enzyme that facilitates the degradation.

Abstract: Compositions and methods are provided that improve detection of botulinum neurotoxins in cell-based assays. In one aspect an isoquinolynyl compound can be used to enhance the sensitivity of both Förster resonance energy transfer (FRET) and non-FRET cell-based assays. Osmolarity of the cell culture media can be adjusted to optimize the effect of the compound. In that subject matter an environment cell can include an enzyme that facilitates degradation of the reporter significantly faster after the cleavage than before the cleavage, and presence of the Botulinum toxin correlates with reduction of the signal from a baseline signal. Where the environment is a cell, the cell can advantageously express both the construct that includes the reporter, and an enzyme that facilitates the degradation.

Abstract: Methods and compositions are provided where a transfected cell that produces a hybrid protein with a reporter-containing portion and a botulinum toxin cleavage site is contacted with a botulinum toxin at elevated temperatures and/or in media having a reduced sodium concentration. Kits that include such media and a botulinum toxin are also described.

Abstract: Methods and compositions are provided where a transfected cell that produces a hybrid protein with a reporter-containing portion and a botulinum toxin cleavage site is contacted with a botulinum toxin at elevated temperatures and/or in media having a reduced sodium concentration. Kits that include such media and a botulinum toxin are also described.