mTeSR Plus

A stabilized, serum-free cell culture medium from STEMCELL Technologies supports the feeder-free maintenance and expansion of human embryonic stem (ES) and induced pluripotent stem (iPS) cells. Built on the mTeSR™1 formulation — described as the most widely published feeder-free medium for human ES and iPS cells — this next-generation product stabilizes critical components, including fibroblast growth factor 2 (FGF2; also known as basic FGF), and delivers more consistent medium pH. According to the manufacturer, the pH of spent medium stays above 7.0 across a 72-hour weekend-free protocol, and FGF2 levels remain elevated at 37 °C over the same period, supporting flexible feeding schedules.

The medium allows greater cell expansion rates with daily feeding while maintaining cell quality during restricted feeding. Feeding intervals can be daily, every other day, or with two consecutive days skipped, with feed volumes adjusted accordingly. Cultures often grow faster than in the original formulation, producing larger colonies and higher confluence sooner after passaging, so users may need to increase dissociation time, raise the split ratio, or shorten the passaging interval. The product is compatible with culture matrices such as Corning® Matrigel® hESC-Qualified Matrix and Vitronectin XF™, and each lot of 5X Supplement is performance-tested using human pluripotent stem cells (hPSCs).

Cells maintained in the medium with restricted feeding retain expression of undifferentiated markers (OCT3/4, TRA-1-60), show a normal karyotype, and remain competent for directed differentiation into neural progenitor cells, cardiomyocytes, hematopoietic progenitor cells, definitive endoderm, pancreatic progenitors, intestinal organoids, and cerebral organoids. The product is manufactured under cGMP and is supplied for research use only.