XI, B, 1 Ruediger: Preservation of Human Serum 3 



control tubes, were used. Of the serum to be tested, 0.6 cubic 

 centimeter was diluted with 2.4 cubic centimeters of physiologic 

 salt solution, and 0.5 cubic centimeter of the diluted serum was 

 put into each of the six test tubes. Each tube of the first pair, 

 tubes 1 and 1', received 0.5 cubic centimeter of 1 : 5 dilution of 

 complement serum. Of the second pair of tubes, tubes 2 and 2', 

 each received 0.5 cubic centimeter of 1 : 10 dilution of complement 

 serum, and each of the third pair of tubes, tubes 3 and 3', re- 

 ceived 0.5 cubic centimeter of 1 : 20 dilution of complement serum. 

 Each antigen tube received 0.5 cubic centimeter of diluted an- 

 tigen representing about one fourth of the anticomplementary 

 dose, and to each of the control tubes 0.5 cubic centimeter of 

 physiologic salt solution was added. Now the tubes were placed 

 in the incubator at 37° C. for one hour. After an hour in the 

 incubator 1 cubic centimeter of sensitized corpuscles was added 

 to each tube ; the tubes were well shaken ; returned to the incu- 

 bator for one hour, during which time they were shaken at 

 least three times; were removed to room temperature; and the 

 results were read about three hours after the corpuscles had 

 been added. 



Technique of conducting the Tschernogubow modification of 

 the Wassermann reaction. — This method utilizes complement 

 and haemolytic amboceptor normally present in human serum. 

 When fresh serum was tested, the complement and hsemolytic 

 amboceptor were derived from the serum tested, while old serum, 

 heated or unheated, was reactivated with normal human serum. 



Ten test tubes, five antigen tubes marked 1, 2, 3, 4, and 5 and 

 five control tubes marked 1', 2', 3', 4', and 5', were used for 

 each test. If the serum to be tested was fresh and unheated, 

 1.6 cubic centimeters of serum were diluted to 4 cubic centimeters 

 with physiologic salt solution. Each tube of the first pair, tubes 

 1 and 1', received 1 cubic centimeter of diluted serum repre- 

 senting 0,4 cubic centimeter of serum. The remaining 2 cubic 

 centimeters of diluted serum were further diluted with 2 cubic 

 centimeters of physiologic salt solution, and 1 cubic centimeter 

 of this dilution was put into each of the second pair of tubes, 

 tubes 2 and 2'. Each of the second pair of tubes received 0.2 

 cubic centimeter of serum. These dilutions were continued 

 until all of the five pairs of tubes were supplied with diluted 

 serum. The quantities of serum represented in the tubes were 

 0.4, 0.2, 0.1, 0.05, and 0.025 cubic centimeter. Each of the an- 

 tigen tubes received 1 cubic centimeter of diluted antigen re- 

 presenting about one fourth of the anticomplementary dose, and 

 each control tube received 1 cubic centimeter of physiologic 



