Letheen broth modified is intended for use in the isolation of microorganisms from cosmetics.
The enzymatic digest of animal tissue, enzymatic digest of casein, yeast extract and beef extract act as carbon, nitrogen and vitamin sources in this medium.
Sodium chloride maintains the osmotic balance of the medium.
The sodium bisulfite and lecithin inactivates quaternary ammonium compounds.
Polysorbate 80 must be added to the medium prior to sterilisation.
Polysorbate 80 neutralises phenols, formalin, hexachlorophene, and in combination with the lecithin, ethanol.
Letheen Broth Modified
Additional Information
| Container | |
|---|---|
| Shelf Life (days) | |
| Storage Temp (°C) | |
| Dehydrated Medium Appearance | |
| Prepared Medium Appearance | |
| Dehydrated Medium Colour | |
| Prepared Medium Colour | |
| Dehydrated PH | |
| Prepared PH | |
| Recommended Incubation |
Product Description
| Organism | Ref. No. | Result |
|---|---|---|
| Escherichia coli | ATCC 8739 | Growth, cream colonies |
| Enterococcus faecalis | NCTC12697 | Growth, white colonies |
| Pseudomonas aeruginosa | ATCC 9027 | Growth, cream colonies |
| Staphylococcus aureus | ATCC 6538 | Growth, white colonies |
Formula*
| FORMULA* | g/L |
|---|---|
| Enzymatic digest of animal tissue | 20 |
| Enzymatic digest of casein | 5 |
| Yeast extract | 2 |
| Sodium chloride | 5 |
| Beef extract | 5 |
| Lecithin | 0.7 |
| Sodium bisulfite | 0.1 |
| Total | 37.8 |
Preparation
Suspend 37.8g of the medium in one litre of deionised / purified water. Add 5g of polysorbate 80 then allow the medium to soak whilst mixing for 10 minutes. Sterilise at 121°C for 15 minutes. Cool to 45-50°C and aseptically dispense into appropriate sterile containers.