Chromatography. Computer artwork of coloured bands representing the separation of different chemicals by the process of chromatography. The process uses a solvent to move the initial sample across some substrate (such as paper). The different physical properties of different chemicals will cause them to move at different rates and separate. Here, the different colours allow this to be observed. There are many variants of the technique, which is used in chemical and biochemical analyses ranging from isolating a new chemical to deoxyribonucleic acid (DNA) sequencing to amino acid identification in protein analyses.