Biomarkers, coined from an almagm of biological and marker, refer to a vast range of chemicals and physiological phenomena. Defined by the NIH as “a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention.” it can be used for diagnosis, prognosis, or even as a screening tool for population research. A biomarker can therefore be a protein or peptide… but also a nucleic acid, lipid, carbohydrate – or a modified form of all of the above.
Biomarkers: what is this?
Prostate specific antigen, for example, can be used as a biomarker for prostate cancer and is considered to be very useful for prognosis. Biomarkers can be detected via ELISA, FACS, positron emission tomography, diffusion magnetic resonance and a variety of other methods.
The vast increase in computaittional power and advances in analytical technologies such as gas chromatography and mass spectronomy have empowered the search for biomarkers tremeandously over the past decades, helping researchers find the proverbial needle in the haystack. The difficulty arises from the challenge of identifying something which is expressed only slightly variantly under abnormal conditions.
How is biomarkers are accepted?
For a newly discovered biomarker to be accepted as a legitimate and useful it needs to be validated as an assay capable of separating the abnormal condition from the normal range of the population – the reference range that is true for 95% of the population. The accepted gold standard requires validation versus a population of at least 200 subjects. Needless to say, considerable fiddling with the assay can be expected before it is tested on such a large study population.
whether you are in the process of perfecting your own assay, and are looking into various alternate techniques, or are seeking a validated assay for an epidemiological study, contact Merkel today for a range of options, as well as advice and technical support in selecting the optimal option for you.