Think about the last time you went to the doctor's office and had a blood test. You were given a piece of paper with a list of concentrations of biochemicals in your blood including cholesterol, glucose, and sodium. How were those values determined and how reliable are they? The ability to accurately and reliably measure the amounts of biochemicals as well as their physical and chemical properties is fundamental to the study of biological systems.
The analysis of biomolecules is usually broken into two steps: separation and measurment. Separation is necessary because cells and biological tissues contain millions of different molecules. In order to accurately measure one of them or a subset of them, the molecules of interest must be separated from the others. This can be achieved by leveraging differences in the physical or chemical properties of the molecules. After the molecules of interest have been isolated, they must be measured. This can be accomplished by leveraging different properties of the molecules including the absorbance, fluorescence, and mass.