library_construction_protocol: Cells were harvested by trypsinization ESCs (Serum+LIF) were cultured in 15% FBS+LIF column purification SCRB-seq adapted for bulk samples (Ziegenhain, C., Vieth, B., Parekh, S., Reinius, B., Guillaumet-Adkins, A., Smets, M., Leonhardt, H., Heyn, H., Hellmann, I., Enard, W., 2017. Comparative Analysis of Single-Cell RNA Sequencing Methods. Mol. Cell 65, 631–643.e4.)