Human-induced pluripotent stem cells (hiPSCs) (https://www.hipsci.org/lines/#/lines/HPSI0714i-nufh_3, https://www.hipsci.org/lines/#/lines/HPSI0914i-euts_1)59 (link) were thawed and cultured under feeder-free conditions on Vitronectin XF™-coated (Stem Cell, #07180) 10 cm tissue culture treated plates (Corning) in complete Essential 8 medium (Life Technologies #A1517001) supplemented with 1% Penicillin/Streptomycin (Invitrogen, #15140122). Cells were incubated at 37°C, 5% CO2 and media changed every day except for the day of passaging. Cells were routinely passaged using 0.5 mM EDTA (Life Technologies #AM9260G) at least 3 times post-thawing before collection. HiPSCs were harvested using Accutase (Millipore, #SCR005) to generate a single cell suspension. Single cells were resuspended in 1X PBS (Thermo Fisher Scientific, #10010023) and passed through a 40uM filter (Corning #CLS431750-50EA) before FAC sorting (BD Influx™ Cell Sorter) into 96-well plates (Framestar, #4TI-0960) containing 2 μl lysis buffer with 1 U/μl Rnase Inhibitor (RRI) and ERCC spike in mix at a 1:20 dilution (Ambion Cat #4456740). Plates were promptly sealed (Thermo Fisher Scientific #AB0626), spun down and frozen at -80 °C until further processing.