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HAEMOLYSIS BY SERUM IN COMBINATION WITH CERTAIN 
BENZOL BODIES. 
By T. J. Mackie. 
While serum -complement acts as haemolysin in the presence of a specific 
immune body, and also along with colloidal silicic acid (Landsteiner and 
Jagic, Browning and Mackie), serum is also capable of producing lysis of 
red blood-corpuscles which have been treated with certain benzol bodies 
(Mackie (1), Browning and Mackie (2) ). 
In the original experiments it was found that if rabbit's corpuscles in 
suspension were treated with minute quantities of tetra-ethyl-diamino- 
triphenyl-methane sulphate (brilliant green) and then rabbit's serum in 
certain amounts was added, rapid haemolysis ensued. The amounts of 
brilliant green used were cjuite non-haemolytic by themselves. Table I 
shows the result of such an experiment. Even larger quantities of the dye 
are capable of producing only partial haemolysis by themselves, and amounts 
of serum which are insufticient to accelerate lysis with these quantities of 
brilliant green actually inhibit the haemolytic action of brilliant green by . 
itself. An amount of brilliant green equal to ten times the smallest quantity 
necessary to produce lysis in the presence of serum produced only half- 
lysis of the test suspension, and that only after two hours' incubation at 37° C, 
while the same quantity of brilliant green in the presence of O*! c.c. of 
serum produced no effect. The lysis by brilliant green and serum was 
found to have attained its maximum in about a quarter of an hour even at 
room temperature. 
Ox's corpuscles were found to be practically insusceptible to In'illiant 
green by itself unless in large amounts, and in the presence of minute 
quantities of the dye rabbit's serum was capable of producing lysis of these 
corpuscles (Table II). 
This effect, unlike haemolysis by serum + colloidal silicic acid, is not 
due to complement, since serum which has been heated at 55° C. for one 
hour, and serum from which complement has been removed by treatment 
with sensitised stomata or by cobra-venom (Omorokow's method), is as 
active as fresh serum (Tables III and IV) . 
As in the case of haemolysis by serum -f colloidal silicic acid, " zone 
phenomena " are noticed (see Tables I, II, IV) ; thus there is an optimum 
