3 1
8. The Latent Antilytic Property of Normal Serum.
Sachs (Ehrlich's Studies on Immunity, p. 603) describes how a heated normal
serum, which has been extracted with certain RBCs, has an antilytic effect on the
lysis of RBCs of the same species by a heated immune serum and complement.
One of the experiments performed by Sachs was as follows :—
Heated rabbit serum (unextracted) incubated
1.o cc
Fresh guinea-pig serum
1 hour.
0.1
„
Complete
A.
then add
lysis.
...
Heated rabbit antisheep serum
...
...
0.01 „
• • •
Sheep RBCs, 5 per cent.
...
...
...
1.0 „
Heated Rabbit serum (extracted with
.
sheep RBCs)
incubated
1.0 cc
...
Fresh guinea-pig serum
1 hour.
0. 1 „
Lysis
B
then add
Nil.
Heated rabbit antisheep serum
•••
•••
...
0.01 „
Sheep RBCs, 5 per cent.
...
I.'
„
We have repeated this experiment with numerous variations with indifferent
success as far as the demonstration of a latent antilytic property was concerned,
unless the conditions of Sachs's experiment were adhered to.
For example :—
(I ) Heated goat-antisheep-serum did not protect its own RBCs from lysis
by fresh pony-antisheep-serum.
(2) Heated normal- g oat-serum was extracted with sheep RBCs and
incubated with fresh goat-antisheep-serum. No inhibition of lysis
when sheep RBCs were added.
(3) Heated normal-rabbit-serum was extracted with sheep RBCs and
incubated with fresh goat-antisheep-serum. No inhibition of lysis
when sheep RBCs were added.
(4) Heated normal-rabbit-serum was extracted with sheep RBCs and
incubated with fresh guinea-pig serum. Slight retardation of lysis
when heated goat-antisheep-serum and sheep RBCs were added,
lysis being complete first in the tubes containing the lesser quantities
o f e x t r a c t e d s e r u m . I n t h e e n d l y s i s w a s c o m p l e t e a l l t h r o u g h t h e
series.
(5) Heated goat-antisheep-serum was extracted with sheep RBCs and
incubated with fresh guinea-pig serum. No inhibition of lysis when
heated goat-antisheep-serum and sheep RBCs were added.
(6) Heated normal-rabbit-serum was extracted with horse RBCs and
incubated with fresh guinea-pig serum. No inhibition of lysis when
heated rabbit-antisheep-serum and sheep RBCs were added.
(7) Heated normal-rabbit-serum was extracted with sheep RBCs and
incubated with. fresh guinea-pig serum. Strong inhibition of lysis
when heated rabbit-antisheep-serum and sheep RBCs were added.
It will be observed that unless the serum to be extracted contains normally an
amboceptor for the RBCs used in extraction no antilytic property is revealed. In
( 2) and (5) goat serum has no amboceptor for sheep RBCs, so extraction with sheep
RBCs had no effect on it.
In (6) the extraction of normal-rabbit-serum with horse RBCs did not protect
sheep RBCs from lysis.
In (3) the fresh goat-antisheep-serum which. was incubated with the extracted
rabbit serum contained both the amboceptor and the complement for the
h æ m
o l y t i c s y s t e m . R e s u l t n o i n h i b i t i o n .
In (4) an amboceptor contained in a serum heterogenous with the extracted
serum was used. Here merely retardation of lysis resulted, the final degree of
lysis after 1½ hours' incubation being the same in the test and in control tubes.