hemagglutinin

The 'bedside card' method of blood typing, in this case using a Serafol card. The result is blood group A positive.

Hemagglutinin refers to a substance that causes red blood cells to agglutinate. This process is called hemagglutination. Examples include antibodies^[1], blood group antigens, autoimmune factors (such as Rh factor), and lectins^[2]. Bacteria, viruses, and other parasites can be the source of blood agglutinins as well.

Types

Examples include:

• Influenza hemagglutinin
• Measles hemagglutinin
• Parainfluenza hemagglutinin-neuraminidase
• Mumps hemagglutinin-neuraminidase
• The PH-E form of phytohaemagglutinin

Uses in serology

Hemagglutination can be used to identify RBC surface antigens (with known antibodies) or to screen for antibodies (with RBCs with known surface antigens).

Using anti-A and anti-B antibodies that bind specifically to either the A or to the B blood group surface antigens on RBCs it is possible to test a small sample of blood and determine the ABO blood group (or blood type) of an individual.

The bedside card method of blood grouping relies on visual agglutination to determine an individual's blood group. The card has dried blood group antibody reagents fixed onto its surface and a drop of the individual's blood is placed on each area on the card. The presence or absence of visual agglutination enables a quick convenient method of determining the ABO and Rhesus status of the individual.

Agglutination of red blood cells is used in the Coombs test.

See also

• Cold agglutinin disease
• Hemagglutination assay

References

This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please improve this article by introducing more precise citations where appropriate. (June 2009)

This medical article is a stub. You can help Wikipedia by expanding it.