Standardization of Leishmania Tropica Suspension with Brown's Standard Opacity Tubes 1

Abstract

The simplest and easiest method for the standardization of Leishmania tropica vaccine is with the Opacity Tubes of Brown. Leishmania tropica is cultured on our leishmania medium (Senekji, 1939) for ten days. The growth from the surface of the solid medium is emulsified in saline solution. The suspension is quite granular, but by shaking the tube, the clumps break up, and a uniform suspension is obtained. All the leishmania should be in the motile flagellated leptomonad stage, because the post-flagellated forms are smaller and may lack the flagellum. The suspension of Leishmania tropica culture is then diluted in saline solution to match the different standard opacity tubes which are manufactured by Messers Burroughs, Wellcome and Company, for the standardization of bacterial vaccines. Counts are made of the standardized leptomonad suspension in the blood counting chamber, and the result is expressed in 1 cc. Results: Tube No. 1 20,500,000 per cc.