Commonly used allergen detection methods can be divided into two groups: There are those that are carried out in a laboratory using specialized equipment, and those that can be performed onsite using little or no specialized equipment. Laboratory-based methods can be further sub-divided into two groups: direct and indirect methods. Direct methods detect specific proteins from the allergenic food in question, most often the allergenic proteins themselves such as with ELISA and there is also a targeted proteomics technique available known as Liquid Chromatography-Tandem Mass-Spectrometry. Indirect methods detect a marker associated with the allergenic food in question, for example, its DNA. PCR is the most commonly adopted method here. Rapid onsite testing methods are cost-effective, mobile and operators need no or very little technical skills for their application. Three types have gained popularity in recent years: allergen-specific lateral-flow devices, total protein indicators and sensitive ATP swabs.