Red blood cells with membrane defects that occur in hereditary spherocytosis are more susceptible to lysis when subjected to severe cold. Increased levels of haemolysis can also be found in stomatocytosis.
Suspected hereditary spherocytosis
Normal range <2 % A result of >8 % is diagnostic of hereditary spherocytosis
|Sample & container required||4 mL EDTA (lavender top) adults 0.5 mL EDTA (lavender top) paediatrics|
|Sample volume||0.5 mL adult tube 0.2 mL paediatric tube|
|Turnaround time||24 hours|
Samples must be tested within 24 hours of collection