Principle

Lowenstein-Jensen medium supports the growth of

Mycobacterium tuberculosis.

The glycerol present in the medium enhances the

growth of Mycobacterium tuberculosis. Accurate amount of

malachite green not only has an inhibitory effect on growth

of organisms other than Mycobacterium tuberculosis,

but also provides the desired color contrast for easy

identification of Mycobacterium tuberculosis colonies.

Storage and Stability

a. Store the LJ kit at 2–8°C away from light.

b. Stability of the unopened medium is as per the expiry

date mentioned on the label.

c. Avoid jerks and vibration while storage, shipping and

incubation.

d. Upon opening, the medium must be put into use

instantly.

Additional Material Required

Sterile plating loops (10 µL), incubator at 37 ± 0.5oC,

biosafety hood with Bunsen burner, activated 2% glutaraldehyde solution, 0.2 mL micropipettes.

Specimen Collection and Preparation

Collect specimen prior to use of antimicrobial agent.

Wherever possible, indicate clearly that patient is on

antitubercular drugs.

CSF

Collect as much as possible in a syringe, clean skin with

alcohol before aspirating specimen.

Body Fluids

Disinfect the site and collect specimen with aseptic

precautions.