Editing Chromatography (section)

====Thin-layer chromatography (TLC) ====
{{further|Thin-layer chromatography}}
[[File:TLC black ink.jpg|thumb|Thin layer chromatography]]
Thin-layer chromatography (TLC) is a widely employed laboratory technique used to separate different biochemicals on the basis of their relative attractions to the stationary and mobile phases. It is similar to [[paper chromatography]]. However, instead of using a stationary phase of paper, it involves a stationary phase of a thin layer of [[adsorbent]] like [[silica gel]], [[Aluminium oxide|alumina]], or [[cellulose]] on a flat, inert [[Substrate (chemistry)|substrate]]. TLC is very versatile; multiple samples can be separated simultaneously on the same layer, making it very useful for screening applications such as testing drug levels and water purity.<ref>{{cite book|title=Handbook of Thin-Layer Chromatography|last=Bernard.|first=Fried |date=2003|publisher=Marcel Dekker Inc|isbn=978-0824748661|oclc=437068122}}</ref>

Possibility of cross-contamination is low since each separation is performed on a new layer. Compared to paper, it has the advantage of faster runs, better separations, better quantitative analysis, and the choice between different adsorbents. For even better [[resolution (chromatography)|resolution]] and faster separation that utilizes less solvent, [[HPTLC|high-performance TLC]] can be used. An older popular use had been to differentiate chromosomes by observing distance in gel (separation of was a separate step).