Other methods exist and are being developed, especially screening tests that can be done rapidly and inexpensively. These are especially useful in countries that may not have access to laboratories.
An example is the the HemoTypeSCTM which is inexpensive, rapid, and disposable, and uses a "dipstick" technique. The principle is that of a competitive enzyme linked immunosorbant assay, in which monoclonal antibodies detect hemoglobins A, S, and C. This test requires less than a microliter of blood, can be completed in under 20 minutes, and does not require electricity or laboratory equipment.
