NIH proposes new hESC definition

NIH proposed to revise its definition of human embryonic stem cells (hESCs) included in its stem cell guidelines. The change would define hESCs as "pluripotent cells that are derived from early stage human embryos, up to and including the blastocyst stage." The NIH guidelines currently define hESCs as "cells that are derived from the inner cell mass of blastocyst stage human embryos." NIH said the current definition excludes from federal funding some hESCs, such as hESCs from an embryo that fails to develop to the blastocyst stage. The proposed change was posted to NIH's website late Friday and published in the Federal Register on Tuesday. Comments on the proposal are due by March 25. ...