Patent ID: 7611856

Claim:
A method for detecting the presence of clostridial botulinum neurotoxins in a sample comprising the steps of: a) mixing a sample that may comprise serotypes of clostridial neurotoxins with a peptide substrate, wherein said peptide substrate is KGSNRTRIDEANORATRMLGGK-(SEQ ID NO: 1), and optionally, one or more peptide substrates selected from the group consisting of SEQ ID NO:14, 21, and 28, for proteolytic activity of said clostridial neurotoxin serotypes, such that at least a portion of the amount of the substrate is proteolytically cleaved by a serotype to produce a mixture comprising uncleaved substrate and peptide cleavage products; b) analyzing the mixture on a mass spectrometer to produce a signal corresponding to the mass of at least one peptide cleavage product; c) using the signal corresponding to the peptide cleavage products to identify the clostridial neurotoxin serotype; d) quantitating the amount of proteolytic cleavage of the peptide substrate for the clostridial neurotoxin serotype by stable isotope dilution mass spectrometry.