Immunoassay Interference Blockers
Blocking solutions designed to neutralize heterophilic antibody interference created by human anti-mouse antibodies (HAMA), rheumatoid factor (RF) and heterophilic antibodies (HA). Multiple formulations are available to suit different applications for ELISA, lateral flow and CLIA.
Why do you need an interference blocker?
Due to the variety of heterophilic antibodies present within patient samples, antibody blockers are essential in developing clinical diagnostic assays. Weakly cross-reacting antibodies such as human anti-mouse antibodies (HAMA) and rheumatoid factor (RF) can interfere with assay kinetics and cause false-positive or false-negative results.
True Positive Result
In a true positive result, assay antibodies are able to freely bind to antigen present in the patient sample. Blockers help by binding to interfering substances and removing their potential to cause a false result.
In a false-negative reaction, heterophilic antibodies bind to the antibodies in the assay, preventing them from binding to the target antigen in the patient sample. The patient sample is positive but the result is reported as negative.
In a false-positive reaction, heterophilic antibodies bind to the assay antibodies in a manner similar to the target antigen. This causes a positive readout despite the patient sample being negative.
What are the Different Types of Blockers?
Unique heterophilic antibody blocker that can remove many different types of heterophilic interference including HAMA and Rheumatoid factor (RF) using a completely new approach.
Animal IgG (e.g. mouse IgG) is suitable for blocking heterophilic antibodies, especially in mixed species assays (e.g. MAb/PAb). The source of the blocker must be the same as the host antibody source.
Excess IgG antibody in patient samples can interfere with IgM detection. Goat anti-human IgG and Meridian’s IgM assay diluent are designed to improve IgM assay sensitivity.
Meridian’s Portfolio of Blocker Solutions
Certificate of Analysis (COAs)
Proven Results Using TRU Block™
Resources to Learn More
Lead about the factors that need to be considered in selecting the right blocker for an immunoassay.
Watch a Short Video
Find out how TRU Block™ works to prevent heterophilic antibody interference.
Gain a deeper understanding of the challenges faced by IVD manufacturers by reading the whitepaper “Reducing Errors in Immunoassay Testing”.
FAQs: Immunoassay Interference Blockers
Immunoassays used for human in vitro diagnostics (IVD) typically use animal-derived antibodies to recognize specific disease markers. Some patients have antibodies in their blood that can react with animal antibodies in the immunoassay and cause a false result. Although the frequency of these interferences is low, false-positive results have a significant negative impact on the quality and competitiveness of a diagnostic assay as well as on the lives of those individuals who have been falsely diagnosed.
Human anti-mouse antibodies (HAMA) is the most well-known antibody interference due to the wide use of mouse monoclonal antibodies in diagnostic applications. Mouse IgG can block HAMA found in patient serum.
No. HAMA only represents one type of heterophilic antibody (HA) interference – others include HA to animals such as goat (HAGA), sheep (HASA), and rabbit (HARA) which can cause false results when antibodies originating from these animals are used in immunoassays. In addition to HA there is another class of interference called Rheumatoid factor (RF), which is an autoantibody that reacts with the patient’s own immunoglobulin (Ig) and can cross react with animal Ig, similar to HA/HAMA interference.