2 V. ;;/{;/ -LABOilAtrpEY .COURSE IN SEBUM STUDY 



LESSON I 



STUDENTS in this course will prepare their own materials for 

 injection, will immunize and bleed animals themselves, in fact 

 will do all the manipulations necessary in the preparation of 

 materials for the experiments that are done in the class. In 

 some cases students will work in groups of two or more in order 

 to save time and animals. 



PREPARATION OF MATERIALS FOR INJECTION 

 1. SHEEP ERYTHROCYTES 



The students who are to immunize their rabbit to blood cells 

 should obtain the blood from the sheep, and at subsequent lessons 

 other students will be given experience in this procedure. 



Bleeding of Sheep. The animal is held by two assistants 

 with the head thrown back and one side of the neck is clipped 

 and carefully shaved. 



A rubber tourniquet is then placed around the neck as near 

 as possible to the shoulders and tied tightly so as to compress the 

 external jugular vein. The vein distends and will be seen to stand 

 out as a ridge the size of a finger. A small part of the shaved area 

 of the skin is painted with tincture of iodine, and a large sterile 

 needle with four inches of rubber tubing attached is plunged 

 through the skin into the vein. The blood is allowed to flow 

 into small Erlenmeyer flasks containing about 20 large beads, 

 and when the desired amount of blood is obtained the flask is 

 shaken thoroughly until coagulation is completed, this procedure 

 defibrinating the blood. If preferred, the blood may be received 

 into citrate solution, containing 1 per cent sodium citrate and 0.5 

 per cent sodium chloride (not more than 1 part of blood to 1 part 

 of solution) or into ammonium oxalate solution (1 per cent). 



To obtain washed erythrocytes and serum for injection 

 the defibrinated blood is poured into sterile centrifuge tubes. 

 The cotton plugs of these tubes should be fastened by turning 

 the free edges back over the neck of the tube and securing 

 them there by means of rubber bands; this will prevent the 



