Middlebrook 7H11 Agar Base ( M511 )
Intended use
Recommended for isolation, cultivation and sensitivity testing of Mycobacteria.
*Composition**
Ingredients g / L
Tryptone 1.000
Ammonium sulphate 0.500
Potassium dihydrogen phosphate 1.500
Disodium hydrogen phosphate 1.500
Sodium citrate 0.400
Magnesium sulphate 0.050
L-Glutamic acid 0.500
Ferric ammonium citrate 0.040
Pyridoxine 0.001
Biotin 0.0005
Malachite green 0.001
Agar 15.000
Final pH ( at 25°C) 6.6±0.2
**Formula adjusted, standardized to suit performance parameters
Directions
Suspend 10.25 grams in 450 ml purified/distilled water containing 2.5 ml glycerol. Heat to boiling to dissolve the medium completely. Sterilize by autoclaving at 15lbs pressure (121°C) for 15 minutes. Cool to 45-50°C. Aseptically add contents of 1 vial of Middlebrook OADC Growth Supplement (FD018). Mix thoroughly before dispensing.
Quality Control
Appearance
Light yellow to light green homogeneous free flowing powder
Gelling
Firm, comparable with 1.5% Agar gel
Colour and Clarity of prepared medium
Light amber coloured clear to slightly opalescent gel with greenish tinge forms in Petri plates
Reaction
Reaction of 2.05% w/v aqueous solution containing 0.5% glycerol at 25°C. pH : 6.6±0.2
pH
6.40-6.80
Cultural Response
Cultural characteristics observed on addition of Middlebrook OADC Growth Supplement (FD018) and glycerol after an incubation at 35-37°C for 2-4 weeks.
Storage and Shelf Life
Store below 10-30°C in a tightly closed container and the prepared medium at 2-8°C. Use before expiry date on the label.