104 "^he Philippine Journal of Science i9i6 



The results obtained are shown in Table VIII. With sera 

 4551, 4552, 4553, 4554, and 4555 the glycerin did not in- 

 fluence the Wassermann reaction. The sera had not become 

 anticomplementary at the end of three months. There was 

 practically no difference between the first and second readings. 

 All sera remained clear and free from bacterial growth. 



CONCLUSIONS 



The following conclusions seem justified: 



Chemically pure glycerin is an ideal preservative for human 

 serum intended for the Wassermann reaction. 



Serum mixed with an equal volume of sterilized, chemically 

 pure glycerin remains clear and sterile for a long time. 



In order to prevent the human serum from becoming anti- 

 complementary, it must be heated to about 55 °C. for thirty 

 minutes before it is mixed with the glycerin. 



Sera heated to 55.5°C. for thirty minutes and mixed with 

 equal volumes of glycerin had not become anticomplementary 

 at the end of three months. 



Unheated human sera mixed with an equal volume of glycerin 

 had not become unfit at the end of about three months. Such 

 sera are moderately anticomplementary even after they have 

 been heated to 55.5°C. for thirty minutes, but can be tested as 

 well as fresh sera, provided more complement and more hsemo- 

 lytic amboceptor are used. The anticomplementary property 

 does not influence the result obtained with the test. 



With sensitized human corpuscles hsemolysis is complete three 

 hours after the complement has been added. If the tubes are to 

 be compared with a haemoglobin scale, they should be placed 

 in the refrigerator for from twelve to twenty-four hours to 

 allow the undissolved blood corpuscles to settle to the bottoms 

 of the tubes. 



I still have a few cubic centimeters of each of these sera and 

 expect to report on them at intervals of a year. 



