In vitro assay to quantify clostridial neurotoxin activity

摘要

In vitro method for determining the biological activity of a preparation of a clostridial neurotoxin, comprising the steps of: (a) contacting at least one test particle with a sample of said preparation; and (b) compare the biological effect of said sample with the biological effect of a reference sample; wherein said at least one test particle comprises at least one membrane that encloses a reaction volume, wherein said membrane carries one or more receptors for said clostridial neurotoxin that can mediate the transfer of said clostridial neurotoxin to said volume of reaction, and wherein said reaction volume comprises a substrate for the proteolytic activity of said clostridial neurotoxin; wherein the biological activity is determined by determining one or more of the following parameters: (i) time-dependent decrease in the amount of starting substrate without changes; (ii) time-dependent increase in the amount (s) of one or more cleavage products resulting from the proteolytic cleavage of said substrate; and (iii) time-dependent decrease in the amount of a compound released from the test particle.