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CVB-DAT-0061.03 Page 1 of 2 

Controlled by: APHIS Center for Veterinary Biologics, 515-337-6100 

United States Department of Agriculture

Animal and Plant Health Inspection Service

Center for Veterinary Biologics

P. O. Box 844

Ames, IA 50010 

1. Reagent Name: Clostridium sordellii antitoxin

2. Strain or Source: Not applicable

3. Lot Number: IRP 501 (04)

4. Fill Date: August 5, 2004 

5. Expiration Date: February 28, 2029 

6. Intended Use: IRP 501 (04) serves as the standard antitoxin when conducting

C. sordellii toxin neutralization tests in mice. 

7. Instructions for Use: C. sordellii antitoxin IRP 501 (04) contains 170 antitoxin units per 

mL (AU/mL). A dilution of standard antitoxin containing 1.0 AU/mL is used in the toxin 

neutralization test as described in title 9, Code of Federal Regulations (9 CFR), section 113.109. 

The dilution is prepared by adding 1.0 mL of well mixed IRP 501 (04) to 9.0 mL of peptone 

diluent (1.0% peptone, 0.25% sodium chloride, pH 7.2). The antitoxin is further diluted by 

adding 1.0 mL of the solution containing 17 au/mL to 16 mL of diluent. The antitoxin diluted 

1:10 is stable if stored at -70°C or lower. 

8. Test of Reagent: 

Determination of antitoxin titer - The antitoxin titer of IRP 501 (04) was determined by injecting 

mice intravenously with 0.2 mL of diluted antitoxin mixed with 1.0 L+ dose of toxin (the 

smallest amount of toxin which, when mixed with 1.0 unit of antitoxin, causes death in at least 

80% of the animals within 72 hours) and 1.0 Lo dose of toxin (the largest amount of toxin which, 

when mixed with 1.0 unit of antitoxin, causes no deaths in animals within 72 hours). The 

antitoxin titer of IRP 501 (04) was confirmed by comparing the results of mice injected with 

toxin-antitoxin mixtures containing 1.0 mL of IRP 501 (04) possessing 1.0 unit of antitoxin to 

the results of mice injected with toxin-antitoxin mixtures containing 1.0 mL of C. sordellii

International antitoxin possessing 1.0 unit of antitoxin. 

Sterility test – IRP 501 (04) was tested for sterility and found to be free of viable bacteria and 

fungi according to procedures outlined in 9 CFR 113.26. 

Precautions: There are no known hazards associated with the use of this reagent. 
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CVB-DAT-0061.03 Page 2 of 2 

Controlled by: APHIS Center for Veterinary Biologics, 515-337-6100 

9. Container Size, Type, Weight, or Volume: Four-mL glass vacules containing 1.3 mL of 

antitoxin. 

10. Storage Conditions: Store at -70°C or lower. 

11. CVB Technical Contact: Bacteriology Section, Center for Veterinary Biologics, 

(515) 337-6100 or FAX (515) 337-7673. 

12. Origin and Passage History: N/A 

13. Method of Preparation: Young adult goats with no history of Clostridial vaccinations 

received multiple injections of C. sordellii toxoid and toxin during an 8-month period. Serum 

from the hyper-immunized goats was precipitated with ammonium sulfate; the precipitate 

resuspended in deionized water and dialyzed against 0.015 M phosphate buffered saline (PBS), 

pH 7.4. The dialyzate was passed through a sterile Millipore filtration unit containing a 0.22-μm 

membrane. Sterile glycerol was added to the antitoxin at a final concentration of 15% v/v. No 

preservative was added to the antitoxin. 

14. Other: None 

Reagent orders and feedback should be sent including phone number to the following email 

address: VS.DB.CVB.Reagent.Requests@usda.gov 

Reagent orders forms (APHIS Form 2018) can be found on the CVB website.