In recent years, advances in spectroscopic techniques led to an increase in their medical applications. In medical sciences, emphasis is increasingly placed on instrumental techniques and accurate, quantitative measurements. It is especially apparent in diagnosis, where imaging techniques and laboratory results have became invaluable and compulsory. Breakthroughs in biochemistry made it possible to characterize physiological processes and living organisms at the molecular level. This led to a proliferation of new methods such as DNA tests and the use of biomarkers in daily clinical practice. Characterization of molecular structure and determination of the composition of a mixture are the fields of analytical chemistry and analytical biochemistry.