As the chemicals being separated may be colourless, several methods exist to visualise the spots:
* Placing the plate under blacklight (366 nm light) makes fluorescent compounds glow
* TLC plates containing a small amount of fluorescent compound (usually manganese-activated zinc silicate) in the adsorbent layer allow for visualisation of some compounds under UV-C light (254 nm). The adsorbent layer will fluoresce light-green, while spots containing compounds that absorb UV-C light will not.
* Placing the plate in a container filled with iodine vapours temporarily stains the spots. They typically become a yellow or brown colour.
* The TLC plate can either be dipped in or sprayed with a stain and sometimes heated depending on the stain used. Many stains exist for a large range of chemical moieties but some examples include:
** Potassium permanganate (no heating, for oxidisable groups)
** Ninhydrin (heating, amines and amino-acids)
** Acidic vanillin (heating, general reagent)
** Phosphomolybdic acid (no heating, general reagent)
* In the case of lipids, the chromatogram may be transferred to a polyvinylidene fluoride membrane and then subjected to further analysis, for example, mass spectrometry. This technique is known as far-eastern blot.