Reproducibility and consistency of protocols is a major limitation in the stem cell differentiation field. We performed one of the first studies using mass spectrometry to test reproducibility of hPSC-derived neuronal differentiation procedures. Inspecting the protein profiles of the end-stage neurons showed limited intra-line variability, as illustrated by growth cone proteins, neuronal (like MAP2 and TUBB3) and pre-synaptic proteins (like synapsin and synaptotagmin) analyzed. So we confirmed reproducibility of our hPSC differentiation procedures, showed that mass spectrometric analysis of indirect contact cultures will facilitate neuronal- (or astrocyte-) specific protein analysis and gives important tools to get insight into changes in overall maturity levels of neuronal networks. Although, more in depth proteomic studies might be required to extrapolate our findings to other hiPSC lines.
