Induced pluripotent stem cells (iPSCs) technology is a method for generating pluripotent stem cells in vitro from fully differentiated cells such as fibroblast cells. The potential applications of iPSC technology in cell therapy and disease modeling could influence current medical practices. Despite current advances in iPSC technology, many patient-derived reprogrammed cells are not suitable for clinical trial because most protocols rely on virus-based techniques, which pose the risk of integration of the viral genome into the chromosomes. Therefore, non-viral methods such as mRNA and protein-based reprogramming are promising alternatives when generating clinically safe iPSCs. In a previous study, we generated human iPSCs using cell extracts with cell penetration peptide (CPP) for the delivery of reprogramming proteins [Kim et al. Cell Stem Cells, 2009]. In here, we show that the expression of reprogramming factors in mammalian cells and subsequent purification of these factors by FLAG-Tag could reprogram fibroblasts into iPSCs. (C) 2017 The Authors. Published by Elsevier Inc.