An osmotic fragility test can aid in the diagnosis.

Although the osmotic fragility test is widely considered the gold standard for diagnosing hereditary spherocytosis, it misses as many as 25% of cases.

The osmotic fragility test is common in hematology, and is often performed to aid with diagnosis of diseases associated with RBC membrane abnormalities.

A tourniquet test (also known as a Rumpel-Leede Capillary-Fragility Test or simply a capillary fragility test) determines capillary fragility.

They have a high rate of returning positive to the Naked eye single tube red cell osmotic fragility test (NESTROFT) test, making them prone to high incidence of Thalassaemia.

It's also notable that there can be a qualitative difference between a mechanical fragility test involving a comparatively lower energy stress, such as by agitating one or more beads in the presence of the sample (a common approach), versus a higher energy stress, such as by applying ultrasound to the sample.