Brain Heart Infusion (BHI) Agar is a general-purpose medium​ that is:

• Prepared using dehydrated ingredients
• Suitable to grow bacteria, yeasts and moulds​
• ​Used for reagent quality control and contamination check for liquid culture​.

To check contamination in Mycobacteria Growth Indicator Tube (MGIT) broth:

The procedure for processing gastric aspirates in TB cultures is as follows:

The procedure for processing pus and other muco-purulent specimens in TB cultures is as follows:

Extrapulmonary specimens are divided into 2 groups based on the site and mode of collection and the extent of contamination:

These are the steps to be followed when processing pulmonary specimens in TB culture laboratories:

Beginning the Specimen Processing Procedure:

1. Process only one specimen at a time, and do not leave open containers or open centrifuge tubes in the Bio Safety Cabinet (BSC).
2. Process the available specimen in a 50 ml sterile, plastic, screw-capped centrifuge tube (Figure).

In the N-Acetyl-L-Cysteine - Sodium Hydroxide (NALC-NaOH) method:

• NaOH works as a decontaminating agent.
• Sodium citrate binds with the heavy metal ions that might be present in the specimen, that could inactivate NALC.
• NALC works as a mucolytic agent that allows NaOH to be used at a lower final concentration of 1% and aids in liquefying sputum to release the trapped bacilli.

Advantages of NALC – NaOH Method

The Mycobacterium Growth Inhibitor Tube (MGIT) instrument needs daily, routine and need-based maintenance.

Maintenance Needs

Instrument Components:​

Active case-finding (ACF) approaches bring essential TB services closer to the community. It has high potential for improving TB case detection and reach people with TB currently missed by the health system. To maximize gains from ACF, it is important that the interventions are planned in advance. 

Mycobacteria Growth Indicator Tube (MGIT) contains:

• 7.0 ml of modified Middlebrook 7H9 broth base
• Growth supplement essential for the growth of Mycobacterium tuberculosis complex
• MGIT PANTA, antibiotic mix to prevent contamination
• Oxygen-quenched fluorochrome (tris 4, 7-diphenyl-1, 10-phenonthroline ruthenium chloride pentahydrate) embedded in silicone at bottom of the tube

Principle