ⓘ Antibody titer

                                     

ⓘ Antibody titer

An antibody titer is a measurement of how much antibody an organism has produced that recognizes a particular epitope, expressed as the inverse of the greatest dilution that still gives a positive result. ELISA is a common means of determining antibody titers.

For example, the indirect Coombs test detects the presence of anti-RH antibodies in the blood serum of a pregnant woman. The patient may be it is the "indirect titer Coombs" 16. This means that in patients blood serum gives a positive indirect Coombs test at any dilution up to 1 / 16th to 1 part whey to 15 parts diluent. At greater dilutions the indirect Coombs test is negative. If a few weeks later the same patient had an indirect Coombs titer of 1 in 32 / 32 dilution of 1 part serum to 31 parts of diluent, it will mean that it is more anti-RH antibody, since it took more dilution on cancellation of a positive test.

Many of the traditional serologic tests such as hemagglutination or complement binding using this principle. Such tests usually can be read visually, which makes them quick and economical "low-tech" environment. The interpretation of serological titers is guided to the reference values that are specific to the antigen or antibody in a titer of 1:32 may be below the cutoff for one test but above the others.