- Antibodies directed against antigens on the surface of red cells cause cross linking so that the cells form a mat instead of a tight button as they fall to the bottom of a microtitre well. This property of antibodies can be used to detect any antigen that can be bound to the red cell surface, or other particles like latex beads. It can also be used to detect antigens like hepatitis B surface antigen when the specific antibody has been linked to the particle surface.
- A positive reaction forms a mat of red cells.
- A tight cell button equates to a negative reaction