SUnSET, a nonradioactive method to monitor protein synthesis

As an alternative to the use of radioactively labeled amino acids, incorporation of puromycin into proteins allows evaluation of translation in heterogenous cell populations by flow cytometry analysis after staining with an antibody to puromycin. We developed a nonradioactive fluorescence-activated cell sorting–based assay, called surface sensing of translation (SUnSET), which allows the monitoring and quantification of global protein synthesis in individual mammalian cells and in heterogeneous cell populations. We demonstrate here, using mouse dendritic and T cells as a model, that SUnSET offers a technical alternative to classical radioactive labeling methods for the study of mRNA translation and cellular activation.