156 
DOURINE AND THE COMPLEMENT FIXATION 
TEST. 
By E. A. WATSON, V.S. 
Pathologist, Veterinary Research Laboratory {Pom. Dept. Agriculture), 
Lethbridge, Canada. 
CONTENTS. 
' PAGE 
Introduction ......... 157 
Brief explanation. . . . . . . . . 158 
Technique and Procedure recommended: 
I. Preparation of Reagents. 
A. The haemolytic system. 
(а) Red cells or washed sheep’s blood 
(б) Haemolytic serum (anti-sheep amboceptor) . 
(c) Complement or guinea-pig’s fresh serum 
B. Dourine ( antibody) combining group. 
( x ) Antigen—dourine trypanosomes .... 
(y) Antibody—dourine horse serum .... 
IT. Titration of Reagents. 
(1) Titration of haemolytic serum ..... 
(2) „ complement ...... 
(3) „ antigen ....... 
III. The Serum to be tested. 
Collection of serum ....... 
Inactivation of serum ........ 
Experiments ........ 
Antibody content of dourine serum and dose necessary for 
diagnostic test ........ 
Experiments ........ 
The first appearance of a positive serum reaction 
Experiments ........ 
IY. The Diagnostic Test. 
Methods of procedure ........ 
Interpretation of the reaction ...... 
General remarks ......... 
Discussion .......... 
160 
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