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products
for neural stem and progenitor cells
for human cells
for mouse cells
for rat cells
for identification and enumeration of neural stem cells
support products (including reagents to dissociate neurospheres and primary tissue)
for primary neurons
for mouse and rat neurons
Training Courses
New! Neural Stem Cell Training Course
Background Information
Neural Stem Cells
Neural stem cells (NSCs) were first isolated from the embryonic and adult mouse striatum in the early 1990’s in a culture system referred to as the Neurosphere Assay.1,2 The Neurosphere Assay was used to demonstrate the presence of NSCs and functionally define NSCs as cells with the ability to: 1) proliferate, 2) self-renew and 3) produce a large number of functional progeny that can differentiate into the three main phenotypes found in the CNS: neurons, astrocytes and oligodendrocytes.1
The Neurosphere Assay
In the Neurosphere Assay, cells are maintained in an undifferentiated proliferative state by culturing them in a serum-free medium supplemented with a mitogen such as EGF. NSCs begin to proliferate after about 24 hours in culture and form small clusters of cells by 2 - 3 days. By day 5 - 7 the clusters, called neurospheres, typically measure 100 - 200 ìm in diameter, are composed of approximately 10,000 cells and are ready to be passaged. To passage, neurospheres are dissociated into a single cell suspension and replated under the same conditions as the primary culture. As long as NSCs are present, this procedure results in a relatively consistent arithmetic increase in total cell number. The presence of NSCs can be demonstrated by the continued generation of new neurospheres in long-term neurosphere cultures.
Neural Stem Cells in Different Species
The Neurosphere Assay has been used to identify NSCs from various regions of mouse, rat and human brain, however, NSCs isolated from different regions and species exhibit different growth regulation properties in vitro.3-5 For example, human NSCs have a slower growth rate than mouse cells, with a doubling time of 5 - 12 days compared to 1 - 2 days for mouse NSCs.6-9 Cells from rat CNS tissue often cannot be expanded for more than 30 days in neurosphere cultures.10 In addition, human, rat and adult mouse NSCs are maintained in vitro in long-term cultures in medium containing EGF and bFGF, while embryonic mouse NSCs can be maintained with EGF alone. Due to the differences in growth rate and culture requirements between species, STEMCELL Technologies has optimized NeuroCult® media, supplements and protocols for mouse, rat and human cells.
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