“Histidyl” is an example of Hirst’s 'Pharmaceutical Paintings', which are composed of his signature colored dots. As a way of exploring the interactions and harmony between pure color, the Pharmaceutical series aims to present a mechanically produced experiment in color. While they appear to be created by a machine, Hirst meticulously attempts to remove any physical evidence of human intervention. Like the rest of the series, “Histidyl,” is sourced from the chemical company Sigma-Aldrich’s catalogue Biochemicals for Research and Diagnostic Reagents, a book Hirst stumbled across in the early 1990’s. The grid formula of the perfectly arranged, complimentary, yet never repeated colors in the Pharmaceutical Paintings are the basis for this endless series.