Updated project metadata. PCT concentration in the bloodstream correlates well with sepsis presence and in severe cases increases up to a thousand times from the healthy physiological values in a short time. In this study, we developed a rapid technique for PCT detection by MALDI-MS, that uses in-situ enrichment directly on the specialized immuno MALDI chips that are utilized directly as MALDI plates. The method’s ability to detect PCT was confirmed by comparing the results with LC-MS bottom-up workflow.