Difference Between Precipitation and Agglutination Reactions

Precipitation vs Agglutination Reactions

Treatment of infectious diseases is dependent upon their correct diagnosis. Antigen-antibody reactions are techniques using which antigens and antibodies are measured. Among these antigen-antibody reactions, serological reactions are in vitro reactions that are most popular methods for diagnosis of diseases and for identification of antigens and antibodies. Precipitation reactions and agglutination reactions are some of the common examples of these serological reactions. There are differences in these tests that will be explained in this article.

Mixing of antibodies with their matching antigens on a surface such as animal cell, erythrocytes, or bacteria results in antibodies cross linking the particles forming visible clumps. This reaction is termed as agglutination. This serological reaction is very similar to precipitation reaction though both are highly specific depending upon specific antibody and antigen pair. The main difference between these two serological reactions pertains to the size of antigens. In the case of precipitation, antigens are soluble molecules while in the case of agglutination; antigens are large, insoluble molecules.

Another difference between precipitation and agglutination is that agglutination reaction is more sensitive than precipitation reaction because a lot of soluble antigens and antibody molecules are required to form a visible precipitation reaction. However, it is possible to make a precipitation reaction sensitive by converting it into agglutination reaction. This can be achieved by attaching soluble antigens to large, inert carriers such as erythrocytes or latex beads. In clinical medicine, agglutination reactions have many applications. They can be used to type blood cells for transfusion, for identification of bacterial cultures and to detect the presence of a specific antibody in the serum of the patient. Agglutination is primary used to check if a patient has a bacterial infection or not.

Agglutination reaction vs Precipitation reaction

• Agglutination reaction and precipitation reaction have great importance in immunology as they are serological reactions that help in the detection of bacterial infection in the serum of a patient.

• Major difference between precipitation and agglutination is the size of antigens involved.

• Antigens are soluble in case of precipitation while they are insoluble in agglutination

• Agglutination is more sensitive than precipitation.