DIAGNOSTIC REAGENTS 325 



persistence of the active process. Jaundice due to biliary obstruction usually may 

 be distinguished from hepatogenous jaundice by this flocculation test. 



Since its introduction in 1938 the Hanger flocculation test has won the 

 unanimous approval and acceptance of its many investigators. The publications 

 of Rosenberg,^ Rosenberg and Soskin,* Phole and Stewart,^ Mateer, Baltz, 

 Marion, Hollands and Yagle,^ Nadler and Butler/ Lawson and Englehardt,^ 

 Yardumian and Weisband,^ and Mateer, Baltz, Marion and MacMillin^o express 

 the high regard which the authors have for the test and characterize it as a 

 valuable adjunct to the other tests in the study of hepatic dysfunction. 



Kopp and Solomon,^^ Mirshy and Von Brecht^^ ^nd Lippencott, EUerbrook, 

 Hesselbrock, Gordon, Gottlieb and Marbel^^ obtained positive cephalin choles- 

 terol flocculation reactions with sera from malarial patients. Guttman, Potter, 

 Hanger, Moore, Pierson and Moore^* confirmed these observations with sera 

 from malarial infected patients and found the changes in the blood to simulate 

 those in acute hepatitis — hypoalbumenemia, decreased capacity of the serum 

 albumin fraction to inhibit the flocculating action of gamma globulin, and an 

 increase in the globulin content of serum in this disease. In malaria infection, the 

 formation of serum protein was more profoundly deranged than many other 

 functions ascribed to the liver and these changes were well demonstrated by a 

 series of cephalin cholesterol flocculation tests. 



Mateer, Baltz, Steele, Brouwer and Colvert^^ in their studies on chronic sub- 

 clinical impairment of the liver, regarded the cephalin cholesterol flocculation 

 test as the most satisfactory single screening test available to detect cases of early 

 hepatic impairment. Mateer, Baltz, Comanduras, Steele and Brouwer^^ recom- 

 mended the cephalin cholestrol flocculation test as (a) the best of all screening 

 tests to detect early hepatic impairment in subclinical cases and preoperative 

 cholelithiasis cases; (b) valuable in chronic hepatitis and cirrhosis cases, and (c) 

 extremely helpful in detecting residual impairment in post-icteric repair stage of 

 acute hepatitis, and helpful in early stages. 



The Hanger flocculation test when properly executed is extremely simple 

 and reliable. It is a more sensitive index of hepatic disturbance than many of the 

 functional studies and gives by far the best correlation with clinical observations. 

 Because of its simplicity, as well as its reliability and efficiency, the flocculation 

 test is advocated as an ideal routine test for determining active disease of the 

 liver. 



Preparation of the Test Antigen 



The test antigen is prepared from the desiccated material in the following 

 manner: 



1. Add 5 ml. of anesthetic ether per unit bottle to effect solution of the con- 

 tents. If turbidity persists, add one drop of distilled water to obtain a clear 

 solution. This solution constitutes the stock ether antigen of Hanger and is stable 

 for months if kept tightly stoppered to prevent evaporation. 



2. The final test antigen is prepared by adding (slowly and with stirring) 

 1 ml. of the stock ether antigen solution to 35 ml. of distilled water warmed to 

 65-70°C. and then heating slowly to boiling. The mixture is allowed to simmer 

 until the final volume is reduced to 30 ml. During the heating, all coarse granular 

 clumps should be dispersed, resulting in a stable, milky, translucent emulsion 

 from which all traces of ether are driven off. The antigen is cooled to room tem- 

 perature and then is ready for use. The liquid emulsion when properly prepared 

 and stored in the refrigerator at 2-6° G. is stable. 



Excessive bacterial contamination of the test antigen emulsion or of the serum- 

 saline-antigen test mixture may give rise to falsely positive flocculation. This may 



