Stem cells are unspecialized cells that can self-renew indefinitely and differentiate into more mature cells with specialized functions. In humans, stem cells have been identified in the inner cell mass of the early embryo (embryonic stem cells), in some tissues of foetuses, the umbilical cord and in several adult organs and tissues (adult stem cells).
Potential of Stem Cells to cure many Diseases
Research on adult and embryonic stem cells has the potential to produce treatments for several medical conditions that, at present, lack therapies. Present research would seem to indicate that many conditions could be treated by transplantations of differentiated stem cells.
Embryonic Stem Cells
Embryonic stem cells (ESC) are isolated from the Introduction develop into all other cell types that occur in the living organism. The establishment of permanent ES cell lines has been facilitated by co-culture with feeder cells and qualified FBS (human ES) or without feeder cells in the presence of LIF (leukaemia inhibitory factor) and FBS (murine ES). LIF prevents spontaneous differentiation of ES cells and maintains their developmental potential. The differentiation into nerve-, muscle-, blood-, fat-, and connective tissue cells can be controlled by specific media and the use of cell type specific growth factors.
Adult Stem Cells
Adult stem cells are undifferentiated cells that can self renew and differentiate into specific cells of the tissues or organs. The primary roles of adult stem cells is to maintain and repair the tissue in which they are found. The in vitro differentiation into mature cells can be controlled by supplementation of growth media with specific growth factors and hormones. The potential of in vitro differentiation is in the regenerative medicine without tissue rejection.
Hematopoietic Stem Cells
Hematopoietic stem cells, the blood-forming cells in the bone marrow, can differentiate into three major types of brain cells (neurons, oligodendrocytes and astrocytes), skeletal muscle cells, cardiac muscle cells and liver cells. For in vitro growth and differentiation specific basal media supplemented with a complex set of hematopoietic growth factors and pre-tested FBS are needed.
Mesenchymal Stem Cells
Bone marrow mesenchymal stem cells can differentiate into different cell types: bone cells (osteocytes), cartilage cells (chondrocytes), fat cells (adipocytes) and other kinds of connective tissue cells. For in vitro cultivation of mesenchymal stem cells specific basal media are needed supplemented with a high concentration of qualified FBS (10-20%). Mesenchymal stem cells can be differentiated in vitro by induction with specific factors.
Neuronal Stem Cells
Neuronal stem cells (NSC), with the potential for self-renewal and to differentiate into neurons and glial cells can be grown in vitro under serum free conditions in the presence of specific growth factors. In vitro grown NSC are used to study basic cell development and neuronal re-transplantation into human beings.
Semi-solid Media in Stem Cell Culture
Methylcellulose media are used for simplified colony formation, separation and identification of hematopoietic and embryonic stem cells. For further analysis dried collagen-based media are ideal for fixation with cytochemical or immuno-cytochemical staining reagents.
FBS ES cell tested
For cultivation of embryonic and adult stem cells ES pre-tested FBS is one of the most important sources of growth factors. By addition of various cytokines the differentiation can be induced.