Human iPSC-Derived Neural Stem Cells: i-HNSC
Frequently Asked Questions
Is i-HNSC culture the same as regular cell culture?
While the two process share commonalities, i-HNSC culture differs from regular cell culture in several aspects. i-HNSC grow poorly on bare plastics, so tissue culture vessels need to be pre-coated with extracellular matrices before i-HNSC are plated. Prepare Poly-L-ornithine/laminin coated plates to culture the cells as described in the i-HNSC Instructions.
From which cell line are your i-HNSC derived?
Our I-HNSC are derived from control Human Induced Pluripotent Stem Cells (hiPSCs), which were genetically reprogrammed from Human Dermal Fibroblasts (HDF) located at the basal layers of the epidermis (skin). For custom I-HNSC generation of unique donor profiles, genetic mutations or diseases, our scientists can isolate HDF directly from specific tissue (sourced by us or customer-supplied).  Alternatively, customers can specify or send pre-isolated cells from which HiPSCs are created and subsequently derived into i-HNSC.
What is the importance of Karyotyping i-HNSC? How many times can i-HNSC be passaged?
Karyotype abnormalities such as chromosome gain, loss, or translocation of a part of a chromosome are a common occurrence in cell culture. Ensuring that i-HNSC have a normal karyotype is fundamental to warrant that observed cell behaviors, phenotypes, or test drug effects are genuine and not an artifact of an abnormal karyotype. In order to minimize the chances of karyotype abnormalities, experiments using I-HNSC should be cultured through a maximum of 20 passages. It’s recommended that karyotype analysis is conducted every 10th passage.
Can i-HNSC be expanded, passaged and cryopreserved?
i-HNSC can be expanded as a monolayer on Poly-L-ornithine/laminin coated culture vessels. The passage of i-HNSC is achieved by enzymatically dissociating the cells into single cells before expanding in new culture dishes. Cells growing in a monolayer should be passaged when the cells reach 85-95% confluency. Do not keep the cells at 100% confluency to avoid premature neural differentiation.  i-HNSC can be cryopreserved in freezing media with high viability and recovery rate upon thawing. Thawed i-HNSC can be further expanded or used for cellular differentiation.
What is the recommended seeding density for i-HNSC? 
It is very important to seed i-HNSC at high seeding densities to achieve optimal recovery post-thaw and during subculture. The recommended seeding density for i-HNSC is 25,000 cells/cm2 during subculture. In addition, optimal seeding densities are also critical for tri-lineage i-HNSC differentiation.
Is there an effect of passage number on i-HNSC differentiation?
There does not appear to be adverse passage number effects. Early and late passage i-HNSC have similar differentiation potential.
What is the differentiation potential of i-HNSC?
i-HNSC are capable of differentiating into various region-specific neuronal and glial cell types in response to the appropriate developmental cues. These neurons can be further used for neurobiology research as well as for drug development or high throughput screening.