Conventional Test Method:

Mouse LD₅₀ Assay for Botulinum Toxin Potency Testing

Alternative Test Method:

Name & Description:

Rat Intercostal Neuromuscular Junction (NMJ) Assay

NMJ preparations are isolated from rats and maintained in vitro in the laboratory to measure the amplitude of a twitch response to electrical stimulation of the nerve. Toxin potency can be directly determined as the decrease in the amplitude of the twitch response after toxin is applied to the medium.

Validation Status:

US: ICCVAM workshop panel recommended that further validation studies be conducted (2008)

UK: Currently undergoing validation

Regulatory Status:

None.

Effect or Potential Effect on Animal Use:

Reduction
(At least 50% decrease in numbers of animals used)

Refinement
(Uses killed instead of live mice)

References:

• Adler S., Bicker G., Bigalke H., Bishop C., Blümel J., Dressler D., Fitzgerald J., Gessler F., Heuschen H., Kegel B., Luch A., Milne C., Pickett A., Ratsch H., Ruhdel I., Sesardic D., Stephens M., Stiens G., Thornton P.D., Thürmer R., Vey M., Spielmann H., Grune B. and Liebsch M. (2010) The current scientific and legal status of alternative methods to the LD50 test for Botulinum neurotoxin potency testing. ATLA 38(4):315-330.
• ICCVAM (2008) Report on the ICCVAM-NICEATM/ECVAM Scientific Workshop on Alternative Methods to Refine, Reduce or Replace the Mouse LD₅₀ Assay for Botulinum Toxin Testing. Bethesda MD: National Institutes of Health (NIH).
• Huber A., France R.M., Riccalton-Banks L., McLaren J., Cox H., Quirk R.A., Shakesheff K.M., Thompson D., Panjwani N., Shipley S. and Pickett A. (2008) The Intercostal NMJ Assay: a new alternative to the conventional LD50 assay for the determination of the therapeutic potency of botulinum toxin preparations. ATLA 36(2):141-152.

Information Last Reviewed:

May 2012