In flow cytometry, does results harmonization requires the same equipment ? Case of cell viability
Résumé
Flow cytometry allow analysis of cellular parameters or functions in order to obtain statistical dimension both populational and individual. University of Reims Champagne Ardennes and INERIS, have set up a mobile environmental flow cytometry core facility: MOBICYTE. This core is dedicated to applications in the field of ecotoxicology, but also ecology functional and integrative ecophysiology. Among all our aim, we work on better understandings of technical confusing factors. More and more manufacturer proposed flow cytometry device particularly this 5 last years. All allow to analyze cell parameters but with different technologies. A lot of team works on same biomarkers, but some variation on protocol and method to analyze data are done. Based on this observation, we would like to harmonize the analyzed process from sample preparation to analyses raw data. First step was based on a consortium of six partners, all equipped with different manufacture flow cytometer, to assess the variability attributable to the equipment. In this study, a human monocyte cell line, THP-1, was chosen in order to have a homogeneous cell population to limit the variability of the measured responses. THP1 are exposed to set of increasing concentration of toxic agent, cadmium and cell mortality are revealed using a fixable fluorescent probe. Once labelled and fixed, cells pre-exposed to cadmium or not, are aliquoted and shipped to consortium for, analysis. Each laboratory analyzed sample set and determine both EC50 of cadmium and an unknown concentration. Raw data have been send to MOBICYTE for global analysis. For each set of sample analyzed on each cytometer, two data analysis was performed. The results obtained with the global analysis reveal a greater variability due to human component. Two immune functions are under study with same design: phagocytosis activity and oxidative burst.