Conventional Test Method:

Mouse LD50 Assay for Botulinum Toxin Potency Testing

Alternative Test Method:

Name & Description:

Endopeptidase Assay-SNAP 25

BoNT endopeptidase assays are based on the in vivo intracellular mode of action and require as a substrate a synthetic or recombinant peptide that contains the endopeptidase-binding site. The SNAP-25 assay has been validated to verify potency as a measure of consistency of clinical samples containing BoNT type A . The assay has been set up for serotypes A, B, C, E, and F.

Validation Status:

UK: Validated to verify potency by the National Institute for Biological Standards and Control (NIBSC) (1999)

US: ICCVAM workshop panel concluded that it is possible, in principle, to use an endopeptidase assay for estimating BoNT concentration in a pharmaceutical preparation. However, they cannot currently be used to replace animals for BoNT potency testing or for detecting BoNT in environmental or biological samples.  Future activities were recommended (2008).

Regulatory Status:

EU: Listed in the European Pharmacopoeia

UK: Routinely used by the NIBSC

US: None

Effect or Potential Effect on Animal Use:


Information Last Reviewed:
May 2012