ABSTRACT
Recently, biomarkers in medicine have gained comprehensive scientific and clinical interest. Biomarker or biological marker defined as alteration in the constituents of tissues or body fluids provide a powerful approach to understanding the spectrum of chronic diseases with application in at least 5 areas like screening, diagnosis, prognostication, prediction of disease recurrence and therapeutic monitoring. Therefore, biomarkers are biological indicators of diseases that can be measured either in vivo by biomedical imaging or in vitro by laboratory methods. Many kinds of biomarkers are available in the field of medical science with lots of positive as well as negative effect. These markers can also reflect the entire spectrum of disease from the earliest manifestations to the terminal stages and will become one of the major driving forces of pharmaceutical research and drug development in the coming years. Generally, a biomarker is potentially useful along the whole spectrum of the disease process- before diagnosis; for screening and risk assessment, during diagnosis; for staging, grading and selecting the initial therapy and during treatment for monitoring therapy, selecting additional therapy or monitoring recurrent diseases. This brief review describes the types and major uses of biomarkers in clinical investigation.