A Live Cell Compatible Flow Cytometric Platform for Sorting Cells Based on Epigenetic Modification Levels

Different cells can have identical genetic content, yet distinctive phenotypic behavior arising from different epigenetic patterns that can reprogram the transcription machinery. These features are essential for organoid formation, yet can become problematic for therapeutic applications and studying epigenetic mechanisms, particularly in stem cells, since epigenetic heterogeneity implies that the same batch of cells can have distinctive responses to extracellular cues, varying abilities to differentiate into the desirable cell types and consequently unexpected clinic consequences. To address this need, we have developed an efficient tool that can be used to identify molecular phenotypes with homogenous epigenetic background and sort them into distinctive populations. To do that, we have engineered protein probes that target at specific histone modifications, such as histone acetylation and methylation. The probes have comparable quantitative accuracy to commercial antibodies. We have analyzed and sorted cells based on their distinctive epigenetic background and validated the feasibility of our sorting approach. The application of our sorting tools on pluripotent cells will also be discussed.