The elimination of cloudy reactions by the use of formalin as a preservative for Bacterium pullorum antigen

Abstract does not appear. First page follows.

Introduction

All who have used the agglutination test for the detection of fowls that harbor Bacterium pullorum have observed the occurrence of excessive turbidity in many tubes which seriously interfered with accurate reading of the reactions. Hitchner, in 1923, reported that the turbidity resulted from the precipitation of fat that is present in the blood serum of some fowls and that it could be avoided by starving fowls for thirty-six hours before blood samples were drawn. Matthews, in 1926, reported studies which he believed demonstrated that such turbidity was due to the presence of a protein rather than a fatty substance in blood serum of fowls. He stated that this protein substance was soluble in weak alkali solution and that clouding of agglutination tests could be avoided by adding a small amount of sodium hydroxide solution to antigen.

Bushnell, Hinshaw and Payne, in 1926, published a very complete discussion of bacillary white diarrhea in fowls which included a resume of the methods used by various agricultural experiment station laboratories in making agglutination tests. This resume shows that in twenty-four of twenty-eight laboratories, phenol is used for preservation of the antigen. The amount of phenol used is 0.5 per cent in nineteen laboratories and 0.4, 0.3, 0.25 and 0.2 per cent phenol in one each of four other laboratories.