Biochemical Techniques and Instrumentation

2.1. Basic principles of chromatography

Chromagraphy techniques are used for the separation of one or more biological compounds from a mixture. The compounds are separated in large as well as small amounts (picograms) by this technique.The term ‘chromatography’ was coined by Mikhail Tswett in 1906. "Chroma" means color and "graphein" means written. The name was coined so as initially, this technique is used for the separation of coloured plant pigments and later applied to colourless compounds. All chromatographic system consists of two phases

1. Stationery phase : which may be solid, gel, liquid supported on a solid
2. Mobile phase: which may be liquid or gas and flows through the stationery phase

Separation of the compounds are mainly based on the differential interaction of molecules between a mobile phase and a stationary phase. Selection of a chromatographic technique is made such that the compounds to be isolated have different distribution coefficients.