| (Microbiology) |
| Investigations | Anti-Streptolysin (ASO) titre antibodies |
| Inform lab before sending | No |
| Specimen type | Clotted blood: 5ml Clot activator and separation gel (GOLD CAPPED) container |
| Ideal time to take specimen | |
| Labelling requirements | click here |
| How to take the specimen | |
| Transport to the laboratory | If transport is delayed then store at +4°C |
| Test Times | Twice weekly |
| Turnround | 2-3 days |
| Additional information | Normal range: <200 Abnormal value, in conjunction with appropriate clinical syndrome: ≥400 Values between 200 and 400 should be interpreted in the clinical context, and repeated after 2 weeks if still indicated. Peak values are seen 4-6 weeks following acute streptococcal upper respiratory tract infection (and therefore may be normal in the setting of scarlet fever) A rise in ASOT in two samples collected >2 weeks apart can support a diagnosis of non-suppurative post-streptococcal sequelae (e.g. acute rheumatic fever) |