Oxoid Blood Agar Base is a nonselective general purpose medium which may be enriched with blood or serum.
Blood Agar Base, Oxoid Composition
| Typical Formula* |
gm/litre |
| `Lab-Lemco’ powder |
10.0 |
| Peptone Neutralised |
10.0 |
| Sodium chloride |
5.0 |
| Agar |
15.0 |
| pH 7.3 ± 0.2 |
Blood Agar Base, Oxoid Preparation:
Suspend 40g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes.
For blood agar, cool the Base to 50°C and add 7% of Defibrinated Horse Blood SR0050. Mix with gentle rotation and pour into petri dishes or other containers.
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 plates of medium at 2-8°C.
Precautions
The haemolytic reactions of organisms inoculated on to this medium will be affected by the animal blood used e.g. horse or sheep and the incubation conditions e.g. aerobic, capnoeic or anaerobic.
When horse blood is added to the medium Haemophilus haemolyticus colonies will produce beta-haemolysis and mimic Streptococcus pyogenes.
