54 TECHNIC OF ANIMAL INOCULATION 



6. In preparing the inoculum care should be exercised that no solid 

 particles enter the syringe. Aside from possibly blocking the needle and 

 interfering with the injection, the subcutaneous injection of small frag- 

 ments may do no particular harm, but in intravenous inoculation they 

 may cause fatal embolism. To obviate this danger the inoculum 

 should, if possible, be filtered through sterile filter-paper before the 

 syringe is filled. 



7. Air-bubbles should be removed. The injection of small bubbles 

 of air into subcutaneous tissues may cause no harm, but when injected 

 into veins they may cause serious disturbances or immediate death. 

 To avoid this the syringe, after being filled, should be held vertically, 

 with the needle uppermost. The needle should be wrapped in cotton 

 soaked in alcohol, and the piston of the syringe pressed upward until 

 all the air is expelled from the barrel and the needle. If a drop of in- 

 oculum is forced out, it will be collected on the cotton, which should 

 immediately be burned. 



8. Injections should be given slowly. 



9. The animal is then tagged or marked, or its coloring recorded. In 

 the case of rabbits, the metal ear tag is best. All data, e. g., the date, 

 size of dose, preparation and kind of inoculum, etc., should be recorded 

 in writing. 



10. When it is necessary to incise the skin in order to reach a vein 

 an anesthetic may be given. With superficial veins, and in subcutaneous 

 inoculations, the injections may be given so readily and easily that no 

 more pain can be felt than that which accompanies similar injections in 

 human beings. 



Animals may be actively immunized in a variety of ways and in 

 different locations in the anifnal body. For a particular antibody, a 

 certain method may be found especially efficacious, and this is dealt 

 with in a subsequent chapter. In serologic work immunization may 

 be performed by subcutaneous, intramuscular, intravenous, intracardial, 

 and intraperitoneal injections. 



METHOD OF PERFORMING SUBCUTANEOUS INOCULATION 



Fluid Inoculum. 1. Injections are usually given in the median line 

 of the abdominal wall. 



2. Have the animal (a rabbit or a guinea-pig) held firmly by an 

 assistant or secured to the operating-table. 



3. Clip the hair where injection is to be made it is not always 



