Specimen: 5 mL blood in plain, lithium
heparin or EDTA tube.
Method: Extraction and conversion of methaemalbumin to haemochromogen; spectroscopy.
Reference Interval: Negative.
Application: Investigation of possible intravascular haemolysis.
Interpretation: Once haptoglobins have been depleted by intravascular haemolysis,
free haem binds to albumin to form methaemalbumin, which is detected by the Schummís
Reference: Dacie JV and Lewis SM. Practical Haematology. 8th ed. Churchill