MLT GlobeMixing study (aPTT/PT correction)
Coagulation · also called 50:50 mix, Correction study, Inhibitor screen
What it measures
Patient plasma is mixed 1:1 with normal pooled plasma and the prolonged PT or aPTT is repeated. Correction points to a factor deficiency; failure to correct suggests an inhibitor.
Specimen and preparation
- Specimen: Citrated plasma (3.2% sodium citrate)
- Tube: Light_blue top
- Preparation: Rule out heparin or other anticoagulant in the sample first.
Reference range
| Group | Range |
|---|---|
| All | Corrects into the normal range (factor deficiency pattern) |
Reference ranges differ between laboratories, methods and populations. Always use the range printed on your own lab report.
Causes of high values
- No correction: lupus anticoagulant
- No correction after incubation: factor VIII inhibitor (acquired hemophilia)
- No correction: heparin or direct anticoagulant contamination
Method
Clot-based PT/aPTT on immediate and 1–2 h incubated 1:1 mixes
Good to know
Time-dependent inhibitors such as anti-factor VIII may correct immediately and prolong again after incubation at 37 °C.
Related tests
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