Extraction of Botulinum Toxin with Urea-Buffer

J Food Prot. 1983 Oct;46(10):861-863. doi: 10.4315/0362-028X-46.10.861.

Abstract

Portions of wieners and soybean foods (tofu and tempeh) remaining from inoculated pack studies using Clostridium botulinum spores were extracted with buffers which differed in having or not having 2 M urea. More samples had botulinum toxin when tested with extracts made in urea-buffer. Based on the LD50 of toxin extracted from wieners, urea-buffer extracted 30 to 100% more toxin than normal buffer.