Publisher Summary Thin-layer chromatography (TLC) is an open-bed chromatographic technique that is generally carried out on a thin layer of stationary phase coated on a glass plate. It is regularly used in many laboratories in the chemical/pharmaceutical and related industries, for both qualitative and semiquantitative work. The main reason for the wide use of the technique of thin-layer chromatography is the quality of information provided by it in a very short time. It is relatively easy to learn and can be performed inexpensively. Although TLC is still being used primarily as an adsorption technique, it has been found useful for separations based on ion exchange, partition, and other modes used in chromatography. Another significant advantage of this technique is that two complementary mobile phases can be employed consecutively, in a two-directional development, to provide additional information. TLC can also be used as a preparative technique for isolation and purification of compounds of interest. The layer of sorbent used for this purpose is generally thicker than a normal TLC plate. However, normal plates can be used when a small quantity of material is needed or when a large number of repetitive runs have to be made. TLC is commonly used for preparative separations because the method of development and operation requires minimal time and cost investment.