公开(公告)号：US20060093581A1

公开(公告)日：2006-05-04

申请号：US11295596

申请日：2005-12-07

申请人： Alan Smith ,  Douglas Smith ,  Ramkumar Mandalam

发明人： Alan Smith ,  Douglas Smith ,  Ramkumar Mandalam

IPC分类号： A61K35/14 ,  C12N5/08

CPC分类号： C12N5/0655 ,  A61K35/15 ,  A61K35/17 ,  A61K35/32 ,  A61K2035/124 ,  C12N5/0636 ,  C12N5/0639 ,  C12N2501/22 ,  C12N2501/23 ,  C12N2501/25 ,  C12N2501/59

摘要： A method for obtaining lineage committed human cells imbued with enhanced proliferative potential, biological function, or both, comprising culturing lineage committed human cells under physiologically acceptable liquid culture conditions, where the liquid culture medium is replaced at a rate and for a time sufficient to obtain the human lineage committed cells imbued with enhanced proliferative potential, biological function, or both; and isolating the cultured cells.

摘要翻译： 一种用于获得具有增强的增殖潜力，生物功能或两者具有增强的增殖潜力的人类细胞的方法，包括在生理上可接受的液体培养条件下培养谱系承诺的人细胞，其中液体培养基以足以获得的速率和时间 人类谱系承诺的细胞具有增强的增殖潜力，生物功能或两者; 并分离培养的细胞。

公开(公告)号：US20050037492A1

公开(公告)日：2005-02-17

申请号：US10949181

申请日：2004-09-24

申请人： Chunhui Xu ,  Yan Li ,  Ramkumar Mandalam

发明人： Chunhui Xu ,  Yan Li ,  Ramkumar Mandalam

IPC分类号： C12N5/0735 ,  C12N5/079 ,  C12N5/0793 ,  C12N15/10 ,  C12N5/08

CPC分类号： C12N5/0606 ,  C12N5/0619 ,  C12N5/0622 ,  C12N15/1034 ,  C12N15/1096 ,  C12N2500/25 ,  C12N2501/115 ,  C12N2501/125 ,  C12N2501/13 ,  C12N2501/145 ,  C12N2501/155 ,  C12N2501/2306 ,  C12N2501/235 ,  C12N2501/237 ,  C12N2501/26 ,  C12N2502/13 ,  C12N2502/99 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2510/00 ,  C12N2510/04 ,  C12N2533/90

摘要： This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of mouse embryonic fibroblast feeder cells to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by defined components added to the culture environment that support rapid proliferation without differentiation. The medium contains an isotonic buffer, a blend of essential nutrients such as protein and lipids, and an effective growth factor or combination of factors that promote proliferation while inhibiting differentiation. Culturing human embryonic stem cells in fresh medium on an extracellular matrix according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

摘要翻译： 本公开提供了一种用于培养人多能干细胞的改进系统。 传统上，多能干细胞在一层小鼠胚胎成纤维细胞饲养细胞上培养以防止它们分化。 在这里描述的系统中，饲养细胞的作用被添加到支持快速增殖而不分化的培养环境中的限定成分所取代。 培养基含有等渗缓冲液，蛋白质和脂质等必需营养素的混合物，以及促进增殖同时抑制分化的有效生长因子或因子组合。 在根据本发明的细胞外基质上的新鲜培养基中培养人胚胎干细胞导致细胞惊人地快速扩张，同时保持分化成代表所有三个胚胎胚层的细胞的能力。 这种新的培养系统允许pPS细胞的大量增殖用于商业生产用于药物筛选和人类治疗的重要产品。

公开(公告)号：US08546139B2

公开(公告)日：2013-10-01

申请号：US12277136

申请日：2008-11-24

申请人： Ramkumar Mandalam ,  Saadia Faouzi ,  Isabelle Nadeau ,  Kristina Pfendler-Bonham ,  Namitha Rao ,  Melissa K. Carpenter ,  Lakshmi Rambhatla ,  Choy-Pik Chiu

发明人： Ramkumar Mandalam ,  Saadia Faouzi ,  Isabelle Nadeau ,  Kristina Pfendler-Bonham ,  Namitha Rao ,  Melissa K. Carpenter ,  Lakshmi Rambhatla ,  Choy-Pik Chiu

IPC分类号： C12N5/00 ,  C12N5/10 ,  C12N5/071 ,  A61K49/00

CPC分类号： C12N5/067 ,  C12N2500/30 ,  C12N2500/36 ,  C12N2500/62 ,  C12N2501/11 ,  C12N2501/115 ,  C12N2501/119 ,  C12N2501/12 ,  C12N2501/13 ,  C12N2501/148 ,  C12N2501/155 ,  C12N2501/23 ,  C12N2501/33 ,  C12N2501/335 ,  C12N2501/385 ,  C12N2501/39 ,  C12N2502/13 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2533/90 ,  C12N2533/92

摘要： This disclosure provides a newly developed strategy and particular options for differentiating pluripotent stem cells into cells of the hepatocyte lineage. Many of the protocols are based on a strategy in which the cells are first differentiated into early germ layer cells, then into hepatocyte precursors, and then into mature cells. The cells obtained have morphological features and phenotypic markers characteristic of human adult hepatocytes. They also show evidence of cytochrome p450 enzyme activity, validating their utility for commercial applications such as drug screening, or use in the manufacture of medicaments and medical devices for clinical therapy.

公开(公告)号：US20120149025A1

公开(公告)日：2012-06-14

申请号：US13323567

申请日：2011-12-12

申请人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph D. Gold ,  Melissa K. Carpenter

发明人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph D. Gold ,  Melissa K. Carpenter

IPC分类号： C12Q1/68 ,  G01N33/566 ,  C12Q1/02

CPC分类号： C12N15/1096 ,  C12N5/0062 ,  C12N5/0068 ,  C12N5/0075 ,  C12N5/0603 ,  C12N5/0606 ,  C12N5/0607 ,  C12N5/0619 ,  C12N5/0622 ,  C12N5/0662 ,  C12N5/0671 ,  C12N5/0672 ,  C12N5/0678 ,  C12N5/068 ,  C12N5/0692 ,  C12N5/0693 ,  C12N5/0696 ,  C12N11/04 ,  C12N15/1034 ,  C12N2500/25 ,  C12N2500/90 ,  C12N2500/98 ,  C12N2500/99 ,  C12N2501/065 ,  C12N2501/105 ,  C12N2501/115 ,  C12N2501/119 ,  C12N2501/125 ,  C12N2501/13 ,  C12N2501/145 ,  C12N2501/155 ,  C12N2501/2306 ,  C12N2501/235 ,  C12N2501/237 ,  C12N2501/26 ,  C12N2501/998 ,  C12N2502/13 ,  C12N2502/99 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2510/00 ,  C12N2510/04 ,  C12N2533/50 ,  C12N2533/90

摘要： This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

摘要翻译： 本公开提供了一种用于培养人多能干细胞的改进系统。 传统上，多能干细胞在一层饲养细胞（如小鼠胚胎成纤维细胞）上培养以防止它们分化。 在这里描述的系统中，饲养细胞的作用由添加到培养环境中的组分代替，其支持快速增殖而不分化。 有效的特征是细胞的合适的支持结构，以及可以在不被另一种细胞类型预处理的情况下可以新鲜添加到培养物中的有效培养基。 在根据本发明的新鲜培养基中培养人胚胎干细胞导致细胞惊人地快速扩张，同时保持分化成代表所有三个胚胎胚层的细胞的能力。 这种新的培养系统允许pPS细胞的大量增殖用于商业生产用于药物筛选和人类治疗的重要产品。

公开(公告)号：US08097458B2

公开(公告)日：2012-01-17

申请号：US12763884

申请日：2010-04-20

申请人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph D. Gold ,  Melissa K. Carpenter

发明人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph D. Gold ,  Melissa K. Carpenter

IPC分类号： C12N15/02

CPC分类号： C12N15/1096 ,  C12N5/0062 ,  C12N5/0068 ,  C12N5/0075 ,  C12N5/0603 ,  C12N5/0606 ,  C12N5/0607 ,  C12N5/0619 ,  C12N5/0622 ,  C12N5/0662 ,  C12N5/0671 ,  C12N5/0672 ,  C12N5/0678 ,  C12N5/068 ,  C12N5/0692 ,  C12N5/0693 ,  C12N5/0696 ,  C12N11/04 ,  C12N15/1034 ,  C12N2500/25 ,  C12N2500/90 ,  C12N2500/98 ,  C12N2500/99 ,  C12N2501/065 ,  C12N2501/105 ,  C12N2501/115 ,  C12N2501/119 ,  C12N2501/125 ,  C12N2501/13 ,  C12N2501/145 ,  C12N2501/155 ,  C12N2501/2306 ,  C12N2501/235 ,  C12N2501/237 ,  C12N2501/26 ,  C12N2501/998 ,  C12N2502/13 ,  C12N2502/99 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2510/00 ,  C12N2510/04 ,  C12N2533/50 ,  C12N2533/90

摘要： This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

摘要翻译： 本公开提供了一种用于培养人多能干细胞的改进系统。 传统上，多能干细胞在一层饲养细胞（如小鼠胚胎成纤维细胞）上培养以防止其分化。 在这里描述的系统中，饲养细胞的作用由添加到培养环境中的组分代替，其支持快速增殖而不分化。 有效的特征是细胞的合适的支持结构，以及可以在不被另一种细胞类型预处理的情况下可以新鲜添加到培养物中的有效培养基。 在根据本发明的新鲜培养基中培养人胚胎干细胞导致细胞惊人地快速扩张，同时保持分化成代表所有三个胚胎胚层的细胞的能力。 这种新的培养系统允许pPS细胞的大量增殖用于商业生产用于药物筛选和人类治疗的重要产品。

公开(公告)号：US20090136955A1

公开(公告)日：2009-05-28

申请号：US12277136

申请日：2008-11-24

申请人： Ramkumar Mandalam ,  Saadia Faouzi ,  Isabelle Nadeau ,  Kristina Pfendler-Bonham ,  Namitha Rao ,  Melissa K. Carpenter ,  Lakshmi Rambhatla ,  Choy-Pik Chiu

发明人： Ramkumar Mandalam ,  Saadia Faouzi ,  Isabelle Nadeau ,  Kristina Pfendler-Bonham ,  Namitha Rao ,  Melissa K. Carpenter ,  Lakshmi Rambhatla ,  Choy-Pik Chiu

IPC分类号： C12Q1/68 ,  C12Q1/02

CPC分类号： C12N5/067 ,  C12N2500/30 ,  C12N2500/36 ,  C12N2500/62 ,  C12N2501/11 ,  C12N2501/115 ,  C12N2501/119 ,  C12N2501/12 ,  C12N2501/13 ,  C12N2501/148 ,  C12N2501/155 ,  C12N2501/23 ,  C12N2501/33 ,  C12N2501/335 ,  C12N2501/385 ,  C12N2501/39 ,  C12N2502/13 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2533/90 ,  C12N2533/92

摘要： This disclosure provides a newly developed strategy and particular options for differentiating pluripotent stem cells into cells of the hepatocyte lineage. Many of the protocols are based on a strategy in which the cells are first differentiated into early germ layer cells, then into hepatocyte precursors, and then into mature cells. The cells obtained have morphological features and phenotypic markers characteristic of human adult hepatocytes. They also show evidence of cytochrome p450 enzyme activity, validating their utility for commercial applications such as drug screening, or use in the manufacture of medicaments and medical devices for clinical therapy.

公开(公告)号：US07410798B2

公开(公告)日：2008-08-12

申请号：US10235094

申请日：2002-09-04

申请人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph D. Gold ,  Melissa K. Carpenter

发明人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph D. Gold ,  Melissa K. Carpenter

IPC分类号： C12N5/00 ,  C12N5/02

CPC分类号： C12N15/1096 ,  C12N5/0062 ,  C12N5/0068 ,  C12N5/0075 ,  C12N5/0603 ,  C12N5/0606 ,  C12N5/0607 ,  C12N5/0619 ,  C12N5/0622 ,  C12N5/0662 ,  C12N5/0671 ,  C12N5/0672 ,  C12N5/0678 ,  C12N5/068 ,  C12N5/0692 ,  C12N5/0693 ,  C12N5/0696 ,  C12N11/04 ,  C12N15/1034 ,  C12N2500/25 ,  C12N2500/90 ,  C12N2500/98 ,  C12N2500/99 ,  C12N2501/065 ,  C12N2501/105 ,  C12N2501/115 ,  C12N2501/119 ,  C12N2501/125 ,  C12N2501/13 ,  C12N2501/145 ,  C12N2501/155 ,  C12N2501/2306 ,  C12N2501/235 ,  C12N2501/237 ,  C12N2501/26 ,  C12N2501/998 ,  C12N2502/13 ,  C12N2502/99 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2510/00 ,  C12N2510/04 ,  C12N2533/50 ,  C12N2533/90

摘要： This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

公开(公告)号：US20050153445A1

公开(公告)日：2005-07-14

申请号：US11010140

申请日：2004-12-10

申请人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph Gold ,  Melissa Carpenter

发明人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph Gold ,  Melissa Carpenter

IPC分类号： C12N15/09 ,  A61K35/12 ,  A61P43/00 ,  C12N5/0735 ,  C12N5/077 ,  C12N5/079 ,  C12N5/0793 ,  C12N5/10 ,  C12N15/10 ,  C12N5/08

CPC分类号： C12N15/1096 ,  C12N5/0062 ,  C12N5/0068 ,  C12N5/0075 ,  C12N5/0603 ,  C12N5/0606 ,  C12N5/0607 ,  C12N5/0619 ,  C12N5/0622 ,  C12N5/0662 ,  C12N5/0671 ,  C12N5/0672 ,  C12N5/0678 ,  C12N5/068 ,  C12N5/0692 ,  C12N5/0693 ,  C12N5/0696 ,  C12N11/04 ,  C12N15/1034 ,  C12N2500/25 ,  C12N2500/90 ,  C12N2500/98 ,  C12N2500/99 ,  C12N2501/065 ,  C12N2501/105 ,  C12N2501/115 ,  C12N2501/119 ,  C12N2501/125 ,  C12N2501/13 ,  C12N2501/145 ,  C12N2501/155 ,  C12N2501/2306 ,  C12N2501/235 ,  C12N2501/237 ,  C12N2501/26 ,  C12N2501/998 ,  C12N2502/13 ,  C12N2502/99 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2510/00 ,  C12N2510/04 ,  C12N2533/50 ,  C12N2533/90

摘要： This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

摘要翻译： 本公开提供了一种用于培养人多能干细胞的改进系统。 传统上，多能干细胞在一层饲养细胞（如小鼠胚胎成纤维细胞）上培养以防止它们分化。 在这里描述的系统中，饲养细胞的作用由添加到培养环境中的组分代替，其支持快速增殖而不分化。 有效的特征是细胞的合适的支持结构，以及可以在不被另一种细胞类型预处理的情况下可以新鲜添加到培养物中的有效培养基。 在根据本发明的新鲜培养基中培养人胚胎干细胞导致细胞惊人地快速扩张，同时保持分化成代表所有三个胚胎胚层的细胞的能力。 这种新的培养系统允许pPS细胞的大量增殖用于商业生产用于药物筛选和人类治疗的重要产品。

公开(公告)号：US20050153444A1

公开(公告)日：2005-07-14

申请号：US11009571

申请日：2004-12-10

申请人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph Gold ,  Melissa Carpenter

发明人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph Gold ,  Melissa Carpenter

IPC分类号： C12N15/09 ,  A61K35/12 ,  A61P43/00 ,  C12N5/0735 ,  C12N5/077 ,  C12N5/079 ,  C12N5/0793 ,  C12N5/10 ,  C12N15/10 ,  C12N5/08

CPC分类号： C12N15/1096 ,  C12N5/0062 ,  C12N5/0068 ,  C12N5/0075 ,  C12N5/0603 ,  C12N5/0606 ,  C12N5/0607 ,  C12N5/0619 ,  C12N5/0622 ,  C12N5/0662 ,  C12N5/0671 ,  C12N5/0672 ,  C12N5/0678 ,  C12N5/068 ,  C12N5/0692 ,  C12N5/0693 ,  C12N5/0696 ,  C12N11/04 ,  C12N15/1034 ,  C12N2500/25 ,  C12N2500/90 ,  C12N2500/98 ,  C12N2500/99 ,  C12N2501/065 ,  C12N2501/105 ,  C12N2501/115 ,  C12N2501/119 ,  C12N2501/125 ,  C12N2501/13 ,  C12N2501/145 ,  C12N2501/155 ,  C12N2501/2306 ,  C12N2501/235 ,  C12N2501/237 ,  C12N2501/26 ,  C12N2501/998 ,  C12N2502/13 ,  C12N2502/99 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2510/00 ,  C12N2510/04 ,  C12N2533/50 ,  C12N2533/90

摘要： This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

摘要翻译： 本公开提供了一种用于培养人多能干细胞的改进系统。 传统上，多能干细胞在一层饲养细胞（如小鼠胚胎成纤维细胞）上培养以防止它们分化。 在这里描述的系统中，饲养细胞的作用由添加到培养环境中的组分代替，其支持快速增殖而不分化。 有效的特征是细胞的合适的支持结构，以及可以在不被另一种细胞类型预处理的情况下可以新鲜添加到培养物中的有效培养基。 在根据本发明的新鲜培养基中培养人胚胎干细胞导致细胞惊人地快速扩张，同时保持分化成代表所有三个胚胎胚层的细胞的能力。 这种新的培养系统允许pPS细胞的大量增殖用于商业生产用于药物筛选和人类治疗的重要产品。

公开(公告)号：US10059939B2

公开(公告)日：2018-08-28

申请号：US13323567

申请日：2011-12-12

申请人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph D. Gold ,  Melissa K. Carpenter

发明人： Ramkumar Mandalam ,  Chunhui Xu ,  Joseph D. Gold ,  Melissa K. Carpenter

IPC分类号： C12N15/10 ,  C12N5/0735 ,  C12N5/079 ,  C12N5/0793 ,  C12N5/074 ,  C12N5/00 ,  C12N5/071 ,  C12N11/04 ,  C12N5/073 ,  C12N5/09 ,  C12N5/0775

CPC分类号： C12N15/1096 ,  C12N5/0062 ,  C12N5/0068 ,  C12N5/0075 ,  C12N5/0603 ,  C12N5/0606 ,  C12N5/0607 ,  C12N5/0619 ,  C12N5/0622 ,  C12N5/0662 ,  C12N5/0671 ,  C12N5/0672 ,  C12N5/0678 ,  C12N5/068 ,  C12N5/0692 ,  C12N5/0693 ,  C12N5/0696 ,  C12N11/04 ,  C12N15/1034 ,  C12N2500/25 ,  C12N2500/90 ,  C12N2500/98 ,  C12N2500/99 ,  C12N2501/065 ,  C12N2501/105 ,  C12N2501/115 ,  C12N2501/119 ,  C12N2501/125 ,  C12N2501/13 ,  C12N2501/145 ,  C12N2501/155 ,  C12N2501/2306 ,  C12N2501/235 ,  C12N2501/237 ,  C12N2501/26 ,  C12N2501/998 ,  C12N2502/13 ,  C12N2502/99 ,  C12N2503/02 ,  C12N2506/02 ,  C12N2510/00 ,  C12N2510/04 ,  C12N2533/50 ,  C12N2533/90

摘要： This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.