324 GENERAL MICROBIOLOGY 



4. Thrust the needle through the skin anterior to the 

 thumb, into the vein and draw about 20 to 30 c.c. of blood 

 into the flask containing the glass beads. 



5. Defibrinate by agitating three or four minutes and 

 filter through two layers of cheese-cloth. 



6. Mix the blood with approximately an equal amount 

 of sterile physiological salt solution and centrifuge in sterile 

 centrifuge tubes. 



7. Draw off the supernatant fluid down to the corpuscles, 

 using the sterile pipette with bulb attached. 



8. Fill the tube with sterile salt solution and mix 

 thoroughly by pouring from one tube to another several 

 times. 



9. Centrifuge again and repeat 6 and 7, at least five times. 



10. Mix the washed corpuscles with an equal volume of 

 sterile physiological s,alt solution, warm to body tempera- 

 ture and inject 14 c.c. into the peritoneal cavity of a rabbit. 



11. Six or seven days later inject the rabbit intra-peri- 

 toneally with 20 c.c. of a 50% suspension of washed sheep 

 blood cells and again on the fourteenth day with 24 c.c. of 

 a 50% suspension. 



12. About a week or ten days from the last injection 

 draw a 'small quantity of blood from the rabbit, allow to 

 clot, pipette off the serum and inactivate at a temperature 

 of 56 C., for thirty minutes and titrate. (For method of 

 titration, see Exercise No. 14.) 



Note. Care must be exercised in the above operations to avoid 

 contaminating the blood cells and they must be thoroughly washed 

 and injected on the same day they are drawn. 



13. State in full your results and any conclusions that 

 may be drawn. 



REFERENCES 

 See Exercise 14. 



