ical
operation or a venesection, or withdrawn by venipuncture from the median
basilic or median cephalic vein of a normal adult) into a centrifuge
tube and centrifugalise thoroughly.

3. Wash with three changes of normal saline (_vide_ also page 388).

4. Transfer the washed cells to a sterile capsule by means of a sterile
pipette. Add 5 c.c. of normal saline and mix thoroughly.

5. Take up the mixture of cells and saline in the all-glass syringe and
inject into the peritoneal cavity of the rabbit.

6. Seven days later inject intraperitoneally the washed cells from 5
c.c. human blood mixed with 5 c.c. normal saline.

7. Seven days later inject the washed cells from 10 c.c. human blood
mixed with 5 c.c. normal saline.

8. After a further interval of seven days repeat the injection of washed
cells from 10 c.c. human blood mixed with 5 c.c. normal saline.

NOTE.--Better results are obtained if the second and
subsequent injections are made intravenously, even when
smaller quantities of washed red cells are employed. If,
however, the intravenous route is selected exceeding great
care must be exercised to avoid the introduction of air into
the vein--an accident which is followed, within a few
minutes, by the death of the rabbit from pulmonary embolism.

9. Allow five days to elapse, then collect a preliminary sample of
blood, say about 2 c.c., from the rabbit's ear. Allow it to clot,
separate off the serum and transfer to a sterile test-tube. Place the
test-tube in a water-bath at 56 deg. C. for fifteen minutes (to
inactivate) and test the serum quantitatively for haemolytic properties
in the following manner:

THE TITRATION OF HAEMOLYTIC SERUM.

_Apparatus Required:_

Electrical centrifuge.
Sterile centrifuge tubes.
Water-bath regulated at 56 deg. C.
Sterilised pipettes 10 c.c. graduated in tenths.
Sterilised pipettes 1 c.c. graduated in tenths.
Sterile test-tubes, 16 x 2 cm.
Small sterile test-tubes, 9 x 1 cm.
Small test-tube rack, or roll of plasticine.
Capillary teat pipettes.
Stout rubber band or length of small rubber tubing.

_Reagents Required and Method of Preparation:_

1. Normal saline solution.

2. Haemolytic serum inactivated by preliminary heating to 56 deg.
C. for 15 minutes (_vide supra_) in test-tube labelled H. S.

3. Complement. Fresh guinea-pig serum in test-tube labelled
C.