... confirmation (WHO, 2010). The failure to confirm TB infection can delay initiation of the appropriate therapy to adequately treat cases, which could prevent the further spreading of the disease ... preparation, culture decontamination and concentration, and culture plating must be done inside a BSC with the possible exception of the centrifugation step. However, centrifugation must be done ... measuring the height of the bubbles, characteristic of the catalase reaction, in the tube. If the height of the bubbles is > 45 mm, the reaction is considered high and if the height of the bubbles...