Geron has been awarded US Patent 7,282,366, “Hepatocytes for therapy and drug screening made from embryonic stem cells.”
Inventors listed on the patent are Lakshmi Rambhatla and Melissa Carpenter.
The patent abstract states that when pluripotent stem cells are cultured in the presence of a hepatocyte differentiation agent, a population of cells is derived that has a remarkably high proportion of cells with the phenotypic characteristics of hepatocytes. In one example, human embryonic stem cells are allowed to form embryoid bodies, and then combined with the differentiation agent n-butyrate, optionally supplemented with maturation factors. In another example, n-butyrate is added to human embryonic stem cells in feeder-free culture. Either way, a remarkably uniform cell population is obtained, which is predominated by cells with the morphological features of hepatocytes, expressing surface markers characteristic of hepatocytes, and having enzymatic and biosynthetic activity important for liver function. Since stem cells readily proliferate in culture, this system provides an abundant source of cells of the hepatocyte lineage for a variety of applications, such as drug screening.
Promega has been awarded US Patent 7,282,348, “Kit for measuring cytotoxicity of a test agent.”
Inventors listed on the patent are Terry Riss and Richard Moravec.
The patent discloses a method and a corresponding kit for determining the cytotoxicity of a test agent, the abstract states. The method includes the steps of adding a pre-determined amount of the test agent to a vessel containing living cells in culture medium. The cells are then incubated for a pre-determined amount of time. A reagent mixture that is non-toxic to the living cells is then added to the cells and culture medium. In the preferred embodiment, the reagent mixture contains a solvent, a dye, an electron transfer agent, a substrate for a cytoplasmic enzyme having a half-life greater than two hours, and NAD+. The contents of the vessel are then measured for production of the reduced state of the dye, the production of the reduced state of the dye being caused by a cytoplasmic enzyme specific for the substrate in the reagent mixture. In the preferred embodiment, the production of the reduced state of the dye is caused by lactate dehydrogenase released from dead and dying cells within the vessel. The kits contain components necessary for performing the method.
ChemoCentryx has been awarded US Patent 7,282,338, “Cell migration assay.”
The inventors listed on the patent are Zheng Wei and Zhenhua Miao.
According to its abstract, the patent describes a modified cell migration assay allowing for improved identification and discrimination of chemokine receptor antagonists from non-specific blockers.