Hi there! Transforming your induced pluripotent stem cells (iPSCs) into high-quality definitive endoderm (DE) lineages is a key milestone for many regenerative medicine and developmental biology projects. By mimicking the signaling environment of the early embryo, you can reliably direct these pluripotent cells toward fates that eventually form the liver, lungs, and pancreas. We know that consistency is everything in stem cell research, so we have optimized this guide to help you achieve robust and reproducible differentiation. Let's get started on generating your endodermal progenitors!
Maintain feeder-free iPSC cultures in a standard pluripotency medium. Perform routine passaging twice per week by detaching cells with 0.5 mM EDTA (HB5135) and plating them at a 1:6 ratio on surfaces coated with 5 µg/ml Vitronectin.
To begin differentiation, dissociate iPSCs using an enzymatic cell detachment solution. Seed the cells at a density of 1,000 cells per well in a 96-well plate previously coated with Vitronectin. Use standard maintenance medium supplemented with 10 µM ROCK inhibitor Y-27632 (HB2297) for this initial seeding.
On Day 1, remove the maintenance medium and replace it with freshly prepared DE 1 differentiation medium. Note: FGF2 can be replaced with stable, cost-effective small molecule FGFR1 agonists TCB-32, TCB-541, or TCB-621 to enable weekend-free feeding and significantly reduce media costs.
On Day 2, perform a complete medium change by replacing the DE 1 medium with freshly prepared DE 2 medium.
On Day 3, exchange the DE 2 medium for freshly prepared DE 3 medium to finalize the specification of the definitive endoderm.
On Day 4, verify successful differentiation using immunocytochemistry. Fix the cells with 4% paraformaldehyde and proceed with blocking and permeabilization using a solution containing serum and 0.1% detergent.
Incubate the samples overnight at 4°C with primary antibodies targeting key endodermal markers, such as SOX17 and GATA4.
Wash the samples and apply appropriate fluorescent-tagged secondary antibodies. Counterstain nuclei using Hoechst 33258 (HB0786) before performing imaging and analysis.
References
Varum, S. et al. Energy Metabolism in Human pluripotent stem cells and their differentiated counterparts. PLoS ONE. 2011;6(6):e20914.
Zorn, A. M. et al. Vertebrate Endoderm Development and Organ Formation. Annual review of cell and development biology 2009:25:221-51.
Fang, Y. et al. Metabolic and Epigenetic Regulation of Endoderm Differentiation. Trends in Cell biology 2022 Feb;32(2):151-164.
Ikonomou, L. et al. Derivation of endodermal progenitors from pluripotent stem cells. Journal of Cellular Physiology. 2015 Feb;230(2):246-58.
McLean, A. B. et al. Activin A Efficiently Specifies Definitive Endoderm from Human Embryonic Stem Cells Only When Phosphatidylinositol 3-Kinase Signaling Is Suppressed. Stem Cells. 2007 Jan;25(1):29-38.
