Noguchi's Modification 295 



and, second, by making use of human instead of sheep corpuscles 

 for the hemolytic test. The advantage of the latter depends upon 

 the fact, carefully determined by Noguchi, that human blood-serum 

 contains no amboceptors active in effecting hemolysis of human blood- 

 corpuscles, though it not infrequently contains hemolytic ambocep- 

 tors for sheep corpuscles. In the directions for making the Wasser- 

 mann test a control test for determining their presence or absence was 

 found expedient. It will also be remembered that the presence of 

 these amboceptors causes no invalidity of the test, provided it be 

 recognized. 



Noguchi also varies the technic in such a manner that very small 

 quantities of the various reagents are employed — ^a necessity that 

 arises from the relatively small quantity of the patient's blood ob- 

 tainable according to the method he employs. The reagents 

 employed are as follows: 



(i) The Serum to be Tested. — To obtain this, Noguchi binds the 

 finger of the patient with a rubber band, makes a good-sized punc- 

 ture near the root of the nail with a Hagedorn needle, and collects 

 about 2 c c. of the blood in a Wright tube (see directions for making 

 the opsonic index). The blood soon coagulates in the tube, which is 

 then scratched with a diamond or file, broken, and the serum re- 

 moved with a capillary pipet. The serum may or may not be in- 

 activated by heat, according to the option of the experimenter. 

 The dose of the unheated serum is i drop; of the inactivated serum, 

 4 drops. The same doses of the normal and syphilitic control serums 

 are used. 



(2) The Complement. — This consists of fresh guinea-pig serum. 

 Of it he makes a 40 per cent, dilution in physiologic salt solution by 

 adding one part of the serum to ij,^ parts of the salt solution; o.i 

 cc. is the unit. Two units constitute the "dose." 



(3) The Antigen. — The antigen is made, according to the direc- 

 tions given in the description of the Wassermann test, out of normal 

 guinea-pig heart. The extract is dried upon filter-paper, as has been 

 recommended for the hemolytic amboceptor, and titrated according 

 to the size of the square of paper needed, instead of the quantity of 

 fluid to be added. 



(4) The Corpuscle Suspension. — For this purpose either normal 

 human corpuscles or the corpuscles of the patient whose blood is to 

 be examined may be employed. Instead of a 5 per cent, suspension 

 a I per cent, suspension is recommended. If normal corpuscles are 

 employed, it is necessary to wash them free of the normal serum or 

 plasma, which Noguchi accompHshes as follows: 8 cc. of normal salt 

 solution are placed in a large test-tube, and the blood flowing from 

 a puncture (in the operator's own finger, for example) permitted to 

 drop in, the proportion being i drop each 4 cc. The fluid is then 

 shaken and stood on ice over night, when the corpuscle sediment 

 and the supernatant fluid containing the fibrin factors and ferment 



