Abstract: Cell based assays for botulinum neurotoxin are provided. Specific neurotoxin uptake or proteolytic activity directed to reporting constructs sensitive to botulinum neurotoxin in cells capable of being intoxicated by botulinum neurotoxin is enhanced by increasing expression of SV2 or heat shock proteins in such cells, respectively.

Abstract: Methods for increasing specific uptake of a Botulinum neurotoxin are provided. Specific neurotoxin uptake by cells capable of being intoxicated by Botulinum neurotoxin is enhanced by increasing temperature from about 37° C. to up to about 41° C., as indicated by a decrease in the EC50 found for cells so treated. The effect requires the presence of both heavy and light chains of the Botulinum neurotoxin, and is serotype selective.

Abstract: Methods for increasing specific uptake of a Botulinum neurotoxin are provided. Specific neurotoxin uptake by cells capable of being intoxicated by Botulinum neurotoxin is enhanced by increasing temperature from about 37° C. to up to about 41° C., as indicated by a decrease in the EC50 found for cells so treated. The effect requires the presence of both heavy and light chains of the Botulinum neurotoxin, and is serotype selective.

Abstract: Methods for a cell-based assay for Botulinum neurotoxin are provided in which a transfected cell that produces a reporting peptide is contacted with a Botulinum neurotoxin in media having a sub-physiological osmolarity and a temperature that is above physiological temperature. This combination provides an unexpected synergistic effect in reducing the EC50 of the cell-based assay relative to an analogous cell-based assay performed at physiological osmolarity and temperature.

Abstract: Apparatus, systems and methods can provide improved detection of botulinum neurotoxins. 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. In another aspect, non-FRET assays and constructs utilize a reporter that is not coupled with the second fluorophore in a manner that produces significant FRET. 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 for a cell-based assay for Botulinum neurotoxin are provided in which a transfected cell that produces a reporting peptide is contacted with a Botulinum neurotoxin in media having a sub-physiological osmolarity and a temperature that is above physiological temperature. This combination provides an unexpected synergistic effect in reducing the EC50 of the cell-based assay relative to an analogous cell-based assay performed at physiological osmolarity and temperature.

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 in media having a reduced sodium concentration, thereby increasing the sensitivity. Such media can also be used in combination with elevated cell culture temperatures. 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 in media having a reduced sodium concentration, thereby increasing the sensitivity. Such media can also be used in combination with elevated cell culture temperatures. Kits that include such media and a botulinum toxin are also described.

Abstract: Apparatus, systems and methods can provide improved detection of botulinum neurotoxins. 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. In another aspect, non-FRET assays and constructs utilize a reporter that is not coupled with the second fluorophore in a manner that produces significant FRET. 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: Apparatus, systems and methods can provide improved detection of botulinum neurotoxins. 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. In another aspect, non-FRET assays and constructs utilize a reporter that is not coupled with the second fluorophore in a manner that produces significant FRET. 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: Apparatus, systems and methods can provide improved detection of botulinum neurotoxins. 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. In another aspect, non-FRET assays and constructs utilize a reporter that is not coupled with the second fluorophore in a manner that produces significant FRET. 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.