What test is used to identify the Rh factor in blood?

The Coombs test is specifically designed to detect the presence of antibodies that may cause hemolytic disease in the context of Rh factor incompatibility. It can identify whether a blood sample has antibodies against red blood cells, which is critical in determining a person's Rh status, especially in pregnant women or when preparing for a blood transfusion.

The Coombs test comes in two forms: direct and indirect. The direct Coombs test checks for antibodies attached to the surface of red blood cells, while the indirect Coombs test looks for antibodies in the serum that could react with incompatible red blood cells, thus identifying the Rh factor and ensuring safe blood handling practices.

In contrast, other tests like a complete blood count (CBC) provide information on the quantity and quality of blood cells but do not ascertain Rh factor status. A blood smear analysis involves microscopic examination of blood cells to diagnose various conditions but does not identify blood typing or Rh factor. Serum electrolytes measure levels of electrolytes in the blood, which are unrelated to Rh factor testing.