The Diagnosis of Tuberculosis: A Comparison of the Results Obtained with Herrold Egg Yolk Agar Medium and with Inoculation Of Guinea-Pigs

Abstract

1 egg yolk added to 200 cc. of 1.5% agar at 60[degree] C, mixed well, makes a valuable medium. Results of cultures on this medium (Herrold) and of inoculations into guinea pigs agreed in 93% of 130 cases; in 5 of the 9 cases in which results disagreed, the Herrold cultures were the more reliable. 36 strains of tubercle bacilli were recovered on the Herrold medium in an average of 12.2 days. Mixing freshly aspirated fluids from tuberculous processes with an equal amount of 20% Na citrate solution prevents coagulation. However, the entire coagulum may be placed on the Herrold medium and growths of tubercle bacilli obtained in that way.