William's E Medium was originally developed by Williams and Gunn as reduced serum-supplemented medium for long-term cell cultures of adult rat liver epithelial cells. Gibco™ William's E Medium can also be used for growing hepatocyte cells of different species, such as human derived HepaRG™ cells.
The complete formulation is available.

Gibco™ William's E Medium is a modification of earlier media that has been enriched in amino acids and double the glucose. William's E Medium contains unique ingredients, including zinc, iron, manganese, non-essential amino acids, the reducing agent glutathione and the lipid methyl linoleate. Gibco™ William's E Medium with GlutaMAX™ supplement minimizes toxic ammonia build-up and improves cell viability and growth in an easy-to-use format.

cGMP Manufacturing
Gibco™ William's E Medium is manufactured at a cGMP compliant facility located in Paisley, Scotland, UK. The facility is registered with the FDA as a medical device manufacturer and is certified to the ISO 13485 standard.

William's E Medium contains no proteins or growth factors. Therefore, William's E Medium requires supplementation, commonly with 5-10% Fetal Bovine Serum (FBS). William's E Medium uses a sodium bicarbonate buffer system (2.2 g / L) and therefore requires a 5-10% CO₂ environment to maintain physiological pH.