1. PUB MED SUMMARY PAGE
J Pharmacol Toxicol Methods. 2014 Mar-Apr;69(2):103-7. doi: 10.1016/j.vascn.2013.12.002. Epub 2013
Dec 12.
A quantitative bifunctionalin vitro potency assay for botulinum
neurotoxin serotype A.
Gregory RW1
, Werner WE2
, Ruegg C1
.
Author information
 1
Revance Therapeutics, 7444 Gateway Blvd., Newark, CA 94560, United States.
 2
Revance Therapeutics, 7444 Gateway Blvd., Newark, CA 94560, United States. Electronic
address: bwerner@revance.com.
Abstract
INTRODUCTION:
Botulinum neurotoxin type A (BoNTA) is one of seven serotypes produced by Clostridium botulinum
(types A thru G) and is the serotype most widely used to treat both cosmetic and medical conditions.
Potency for botulinum toxin preparations is expressed in mouse LD50 units. There is a need to develop a
non-animal based replacement for this potency assay.
METHODS:
An in vitro potency assay measuring BoNTA activity has been developed that addresses both BoNTA
heavy chain binding to its cell receptor SV2C and BoNTA light chain enzymatic activity in cleaving SNAP -
25, an intracellular protein essential in neurotransmitter release. This bifunctional assay utilizes a 96 well
microtiter format and well defined reagents. Assay characterization determined that the relative standard
deviation for intermediate precision was less than 10%.
RESULTS:
The assay standard curve covers the range of BoNTA concentrations from 0.0624 to 32 ng/mL.
Specificity was demonstrated with purified BoNTA heavy chain which inhibited the activity in a dose
dependent manner. A correlation between this bifunctional assay and the mouse LD50 potency assay
was demonstrated.
Copyright © 2013 Elsevier Inc. All rights reserved.
KEYWORDS:
Botulinum neurotoxin type A (BoNTA) in vitro potency assay; LD(50); Methods; SV2C