EUROIMMUN radioimmoassays (RIA/IRMA)

In the first incubation step patient sera are incubated with ¹²⁵I-labelled antigen in polystyrene tubes. Any specific antibodies in the sera bind to the antigen.
In the second incubation step the antigen-antibody complexes are precipitated using a precipitation agent.
The precipitate is washed with buffer. After centrifugation and decanting of the supernatant, the radioactivity in the precipitate is counted using a gamma counter. The intensity of the radioactivity is proportional to the concentration of specific antibody in the patient serum.
The antibody concentration is evaluated quantitatively using a calibration curve.

RIA tests (coated tubes) are competitive ligand assays for antibody and antigen determinations.
The intensity of radioactive radiation is inversely proportional to the concentration of specific antibodies or antigens in the sample.
The quantitative evaluation of the antigen/antibody concentration is carried out using a calibration curve.

With this test principle, monoclonal antibodies which are bound directly or indirectly to the inner wall of polystyrene tubes are used.
During the first incubation step, the patient sera to be investigated are incubated with the monoclonal ¹²⁵I-labelled antibodies in the coated tubes.
The antigen in the sample is bound by the immobilised antibodies and by the ¹²⁵I-labelled antibodies. This results in a solid-phase bound sandwich complex.
The unbound ¹²⁵I-labelled antibodies are removed by washing and subsequently decanting. The intensity of radioactive radiation is proportional to the concentration of antigens in the patient serum.
The quantitative evaluation of the antigen concentration is carried out using a calibration curve.

Simple and economical handling, reliable analysis
Simple test procedure.
Synchronous processing of samples, including different tests in parallel.
Ready-to-use reagents (possible exceptions: tracer, precipitation reagents).
Different test formats for small and large sample series.
Because of the large measurement range of EUROIMMUN RIA, further measurements with other sample dilutions are generally not necessary.
Simple evaluation of test results.
Each test can be optionally evaluated with controls which are supplied in the test kit. Test kit-specific reference ranges are given for all controls.
EUROIMMUN radioimmunoassays show the following analytical characteristics:
– High analytical specificity.
– High detection sensitivity.
– High clinical sensitivity and specificity.
– Good reproducibility.