Osmotic Fragility

Why should I do it ?
To detect RBCs that are more fragile than normal, which may be found in hereditary spherocytosis.

When should I do it ?
As a follow up to a routine CBC and blood smear, which has revealed a case of anemia

What Kind of Sample is Needed ?
A blood sample obtained by inserting a needle into a vein in the arm or sometimes from pricking a finger or the heel of an infant

Test Preparation Needed?