The immunoassay antibodies bind to a tiny part of the hormone called an epitope. Hormones are made up of thousands of 'building blocks', with epitopes making up less than 10 of these blocks. The difference between hormones can be as little as one of these epitope blocks.
The research team took a variety of precise measurements of the hCG hormone, drawing on NPL's world-leading measurement technology and expertise, which were supported by atomistic computer simulations.
The team showed how very subtle, atomic level characteristics define the antibody selectivity in closely related epitopes of different proteins. They identified that specific antibodies are highly selective in immunoassays and can distinguish between hCGβ and closely related LH fragments.
Understanding these structural differences explains the observed selectivity in the full hormones. Armed with this knowledge, scientists can develop intelligent epitope selection to achieve the required assay performance. This means reliable tests can be developed to indentify the presence of different hormones in this case the presence of hCGβ which indicates cancer, as opposed to LH, which is always present.
The advances described in this research will enable development of further immunoassays to identify other biomarkers from similar groups. Pharmaceutical companies could use this to develop new technologies for diagnostics and clinical disease treatments, for example tests for tumour as part of routine screenings.
Max Ryadnov, Principal Research Scientist at the National Physical Laboratory, says "This work answers one of the big questions in distinguishing biomarkers which are critical for identifying and treating serious diseases. We hope this breakthrough will underpin the development of a range of new diagnost
|Contact: David Lewis|
National Physical Laboratory