A Novel In Vitro Method for Detecting Undifferentiated Human Pluripotent Stem Cells as Impurities in Cell Therapy Products Using a Highly Efficient Culture System

In the article, the authors use LN-521 for a safety step for iPS cells going for therapeutic purposes. This group is responsible for dictating the safety aspects of future regen med in Japan. Tano and colleagues show a novel approach based on LN-521 for direct and sensitive detection of trace amounts of residual undifferentiated hPSCs for cell therapy products. The presence of contaminating hPSCs in cell therapy products is a major quality concern associated with tumorigenicity and this first in vitro assay is direct, simple and cost-effective. The highly efficient culture system using LN-521 detected colony-forming hPSCs spiked into primary human MSCs or neurons at a ratio as low as 0.001%–0.01%.