Brain heart infusion agar is very nutritious general-purpose medium and is suitable for the isolation of most micro-organisms including many fastidious organisms.
The formulation is a modification of that from Rosenow and Hayden.
The medium is not recommended for the determination of haemolytic reactions because of the glucose content.
The nitrogen, vitamin and carbon sources are supplied by the Brain-Heart infusion solids and peptone.
Glucose serves as the carbohydrate source and sodium chloride aids in maintaining the osmotic balance.
A phosphate buffer, disodium hydrogen phosphate, is incorporated to help neutralize any acids produced as a result of glucose utilization and thus maintain viability of the organisms.
NB: Organisms that produce large amounts of acid in the medium may overwhelm the buffering system and as a result may ‘auto-sterilize’ the culture.
Brain Heart Infusion (BHI) Agar
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
| Organisms | Ref. No | Result |
| Staphylococcus aureus | NCTC 12981 | Growth, white colonies |
| Escherichia coli | NCTC 12241 | Growth, grey colonies |
Formula*
| g/L | |
| Brain-heart infusion solids | 17.5 |
| Peptone | 10.0 |
| Glucose | 2.0 |
| Sodium chloride | 5.0 |
| Disodium hydrogen phosphate | 2.5 |
| Agar | 12.0 |
| Total | 49.0 |
| *Adjusted/supplemented as required to meet performance requirements | |
Preparation
Suspend 49g of the medium in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Sterilise at 121°C for 15 minutes with frequent stirring to completely dissolve the medium. Cool to 45-50°C and dispense into appropriate sterile containers.