The QuickZyme hydroxyproline assay is used for the quantitative determination of hydroxyproline. Hydroxyproline results from (acid) hydrolysis of collagen. Usually for this analysis upon hydrolysis removal of HCl is needed, which is a time-consuming step and/or requires special equipment. The QuickZyme hydroxyproline assay kit is the only hydroxyproline-based assay which does not need this laborious step, resulting in a fast (<2 hrs), sensitive and easy (96-well plate format) assay.