TRYPTONE GLUCOSE EXTRACT AGAR
Code: CM0127
For the plate count of water, dairy products and for the detection of thermophilic organisms.
Typical Formula* | gm/litre |
`Lab-Lemco’ powder | 3.0 |
Tryptone | 5.0 |
Glucose | 1.0 |
Agar | 15.0 |
pH 7.0 ± 0.2 @ 25°C | |
* Adjusted as required to meet performance standards
Directions
Suspend 24 g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Mix well before pouring. When the dilution of the original specimen is greater than 1 in 10, add 10 ml of sterile 10% solution of Skim Milk Powder LP0031 per litre.
Description
This medium, of American origin, is recommended for the plate count of water and dairy products1,2. It can also be used for the detection of thermophilic bacteria in dairy products. The Standard Methods Committee of the American Public Health Association recommended that sterile milk should be added to this medium only when the dilution of the original specimen was greater than 1 in 10. The addition of 10 ml of a sterile 10% solution of Skim Milk Powder LP0031 per litre is suitable for this purpose. It is essential that this medium is not overheated during sterilisation.
See also Plate Count Agar CM0325.
Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.
Appearance
Dehydrated medium: Straw coloured, free-flowing powder
Prepared medium: Straw coloured gel
Quality control
| Positive control: | Expected results |
| Enterococcus faecalis ATCC® 19433 * | Good growth; white/cream colonies |
| Negative control: | |
| Uninoculated medium | No change |