{"id":127026,"date":"2026-07-24T14:52:38","date_gmt":"2026-07-24T20:52:38","guid":{"rendered":"https:\/\/purmabiologics.com\/blog\/what-is-williams-e-medium\/"},"modified":"2026-08-26T18:42:48","modified_gmt":"2026-08-27T00:42:48","slug":"what-is-williams-e-medium","status":"publish","type":"post","link":"https:\/\/purmabiologics.com\/blog\/what-is-williams-e-medium\/","title":{"rendered":"What Is William&#8217;s E Medium? A Clear Guide"},"content":{"rendered":"<div class=\"purma-guide\">\n<p class=\"pg-lead\">William&#8217;s E Medium is a nutrient-rich medium best known as the standard choice for culturing liver cells (hepatocytes). It was developed by Gwendolyn Williams for the long-term culture of adult rat liver epithelial cells, and it remains widely used for primary hepatocytes and other specialized cultures. This guide explains what William&#8217;s E Medium is, what is in it, and how to use it.<\/p>\n<div class=\"pg-keyfacts\">\n<h3>Key Facts<\/h3>\n<ul>\n<li><strong>Type:<\/strong> Nutrient-rich basal medium<\/li>\n<li><strong>Best for:<\/strong> Primary hepatocytes and liver models<\/li>\n<li><strong>Buffering:<\/strong> Bicarbonate (use a CO2 incubator)<\/li>\n<li><strong>Supplement:<\/strong> Serum or defined additives + L-glutamine<\/li>\n<\/ul>\n<\/div>\n<h2>What is William&#8217;s E Medium?<\/h2>\n<p>William&#8217;s E Medium (sometimes written Williams&#8217; Medium E) is a chemically balanced basal medium designed to support demanding primary cells, especially hepatocytes, over extended periods. It was developed as part of a series of media, with formulation E proving the most successful for liver cell culture. Like other basal media, it supplies salts, amino acids, vitamins, and glucose, and it is completed with serum and glutamine before use.<\/p>\n<h2>What is William&#8217;s E Medium used for?<\/h2>\n<p>William&#8217;s E Medium is most associated with:<\/p>\n<ul>\n<li><strong>Primary hepatocytes<\/strong>, where it is a standard culture and maintenance medium<\/li>\n<li><strong>Liver-related models<\/strong>, including toxicity and metabolism studies<\/li>\n<li>Other specialized primary cultures that need a rich environment<\/li>\n<\/ul>\n<h2>What is in William&#8217;s E Medium?<\/h2>\n<p>A typical William&#8217;s E formulation contains a broad set of inorganic salts, essential and non-essential amino acids, a rich vitamin profile, glucose, glutathione, and a bicarbonate buffer with phenol red. Because it uses a bicarbonate buffer, it needs a CO2 incubator (usually 5%) to hold the correct pH.<\/p>\n<h2>How to supplement and use William&#8217;s E Medium<\/h2>\n<p>Before use, William&#8217;s E Medium is completed with serum (or, for many hepatocyte protocols, defined supplements) and L-glutamine or a stable glutamine dipeptide. For hepatocyte work it is often used with hormones and other additives depending on the protocol. Keep it in a CO2 incubator, store it refrigerated and protected from light, warm it gently before use, and keep the same lot across an experiment for consistency.<\/p>\n<\/div>\n<div class=\"purma-related\">\n<p class=\"pr-h\">Related guides<\/p>\n<ul class=\"pr-list\">\n<li><a href=\"\/what-is-dmem\/\">What Is DMEM?<\/a><\/li>\n<li><a href=\"\/what-is-dmem-f12\/\">What Is DMEM\/F-12?<\/a><\/li>\n<li><a href=\"\/what-is-emem\/\">What Is EMEM?<\/a><\/li>\n<\/ul>\n<p class=\"pr-all\">Browse every guide in the <a href=\"\/cell-culture-guides\/\">Cell Culture Guides library<\/a>.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>William&#8217;s E Medium is a nutrient-rich medium best known as the standard choice for culturing liver cells (hepatocytes). It was developed by Gwendolyn Williams for the long-term culture of adult rat liver epithelial cells, and it remains widely used for primary hepatocytes and other specialized cultures. This guide explains what William&#8217;s E Medium is, what [&hellip;]<\/p>\n","protected":false},"author":3155,"featured_media":127121,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[856],"tags":[],"class_list":["post-127026","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","entry","has-media","owp-thumbs-layout-horizontal","owp-btn-normal","owp-tabs-layout-horizontal","has-no-thumbnails","has-product-nav"],"acf":[],"_links":{"self":[{"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/posts\/127026","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/users\/3155"}],"replies":[{"embeddable":true,"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/comments?post=127026"}],"version-history":[{"count":0,"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/posts\/127026\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/media\/127121"}],"wp:attachment":[{"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/media?parent=127026"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/categories?post=127026"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/purmabiologics.com\/blog\/wp-json\/wp\/v2\/tags?post=127026"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}