Quantitative Proteomic Analysis of Islet and Stem Cell Cultures

S6, S7d7, S7d14 and Wnt-modulated cell cultures were washed in DPBS and harvested with TrypLE™ Select Enzyme (1X) (12563011, Thermo Fisher Scientific), followed by centrifugation. Islets and hiPSC-derived cells were lysed as described previously (18 (link)). The protein concentration was determined using a BCA protein assay kit. Dry aliquots containing an estimated amount of 100 μg of proteins were further processed using Filter-Aided Sample Preparation (20 (link)). The six islet samples were combined and mixed to make a homogenous mixture, and 50 μg protein of the mix were aliqvoted into six separate samples for downstream TMT11-plex analysis.