PREPARATION OF TETANUS ANTITOXIN 309 



EXERCISE 7. THE PREPARATION OF TETANUS ANTI- 

 TOXIN 



Note. In the preparation of tetanus antitoxin for therapeutic 

 purposes, healthy horses are used. For the first injection of toxin 

 a small fraction of a cubic centimeter is given subcutaneously. The 

 increase in the size of the dose and the frequency of injection depend 

 upon the condition of the animal, but the quantity injected is gradually 

 increased until the animal is able to stand 300 to 400 c.c. of toxin at 

 one injection. 



For laboratory purposes, the rabbit may be used to furnish the 

 antitoxin. 



The following method suggested by Roux and Vaillard 

 produces a satisfactory antitoxin for laboratory study. 



Apparatus. Tetanus toxin; Gram's iodin solution; 

 rabbits; 20 c.c. syringe; disinfectant; anesthetic; oper- 

 ating tray; 50 c.c. sterile glass cylinder. 



Method. 1. Give the first five or six injections sub- 

 cutaneously, subsequent ones may be given intraperi- 

 toneally. 



1st day, 3 c.c. of toxin mixed with 1 c.c. of Gram's iodin 

 solution. 



5th day, 5 c.c. of toxin mixed with 2 c.c. of Gram's iodin 

 solution. 



9th day, 12 c.c. of toxin mixed with 3 c.c. of Gram's 

 iodin solution. 



16th day, 5 c.c. of undiluted toxin. 



23d day, 10 c.c. of undiluted toxin. 



30th day, 15 c.c. of undiluted toxin. 



The quantity may be gradually increased until the 

 rabbit is getting 100 c.c. of undiluted toxin. 



2. After the 6th injection has been given, wait a period 

 of ten days and bleed the rabbit aseptically. This is accom- 

 plished as follows: 



(a) Secure the rabbit in a dorsal position on an operating 

 tray and anesthetize with ether. 



(b) Expose an area about 3 cm. square over the inferior 



