Learn how to perform better stem cell research from StemCultures.
Stem cells are a unique cell type that have received a lot of attention in biomedical research and development over the last few years. These cells are one of the few cell types that can self-renew. Because of this, stem cells can be manipulated for a wide variety of cell culture research applications. More and more therapeutic discoveries are utilizing stem cells for more efficient results. However, the unique properties of these cells also make them a more difficult cell type to culture.
Two Main Types of Stem Cells
There two main types of stem cells: Pluripotent Stem Cells, which includes embryonic stem cells and induced pluripotent stem cells (iPSCs), and Somatic Stem Cells, often referred to as adult stem cells. iPSCs are of most interest to scientists because of their ability to differentiate into any cell type in the body. Adult stem cells can only differentiate into the type of cells of tissues they’re found in. The ability for iPSCs to differentiate into any cell type is a huge benefit to scientists, but it also makes growing these cells in a laboratory environment more difficult. Culture conditions must be controlled as much as possible to prevent the cells from differentiating before scientists need them to.
Typically, iPSCs are grown in culture dishes containing culture medium, a broth filled with growth factors and nutrients designed for optimal cell growth. The medium is replaced daily to maintain proper nutrient levels and prevent unwanted differentiation. Once cells grow to an appropriate density, they are subcultured through a process called passaging wherein the cells are re-plated into new wells. Typically, this occurs about once a week, but can vary depending on the cell densities. Additionally, cells can be frozen for future use or can be shipped to other laboratories once they are at a desired state. These practices are utilized by laboratories across the world and have become the accepted method for iPSC culture.
Best Practices for Stem Cell Research
Over the years, StemCultures, along with partners at the Neural Stem Cell Institute, recognized many of the limitations these practiced culture methods have. In attempts to optimize the process of growing stem cells, StemCultures recommends the following tips and tricks to make culturing stem cells much easier for scientists while also improving outcomes.
- Examine your cultures daily.
Looking for irregularities in the cells or changes in their morphology can be key to locating differentiating cells. iPSCs grow in tight, compact colonies when they are undifferentiated. Often, smaller colonies will seem loose, but tighten as they grow. Differentiated cells will not be attached and should be removed from the plate using an aspirating pipette.
Monitoring confluence in cultures is another way to determine when the cells need to be passaged. It is recommended to passage cells once they reach 80% confluence, typically after 5 days. When passaging, be sure to handle your cultures with care.
- Stay consistent in your practices.
There is a lot of uncertainty about what reagents are responsible for effective cell proliferation. Inconsistencies in culture media content is the cause of this uncertainty and is one of the biggest obstacles in stem cell research. To overcome this as much as possible, it is important to keep all known variables consistent throughout the experiment. One example of this is feeding your cells at the same time each day. Short half-lives of growth factors contained within typical culture media lead to low levels of the growth factor immediately before the next feed. By feeding at consistent times, the amount of time the cultures go with no growth factors is reduced.
- Use medium additives such as FGF2 DISCs.
StemCultures’ FGF2 DISCs release growth factors into cell culture media to maintain constant levels in culture for several days. By adding a DISC, scientists no longer must perform daily medium changes and their culture quality is improved. When added into 2 mL of medium, standard size DISCs release FGF2 at 10 ng/mL, ideal when using 6 or 12 well plates. StemCultures has recently developed mini sized DISCs that release FGF2 at 10 ng/mL when added into 1 mL of medium, ideal when using 24 or 48 well plates. With this new product, FGF2 DISCs can be used for almost any iPSC experiment or bulk up.
- Be patient!
Growing iPSCs can be a slow and tedious process. Getting new lines up and running after a thaw can be frustrating. Keeping with your cultures and practicing these tips and tricks will help to mitigate the struggles that come with iPSC culture.
The workload associated with stem cell culture is immense, but the payoffs of the resulting research are revolutionary. StemCultures continues to try and eliminate the pains associated with this type of cell culture. The easier it is to laboratory grow stem cells, the better the therapeutics that are developed as a result.
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Note: Opinions and accounts expressed herein are those of the author(s) or interviewee(s) and may not reflect those of StemCultures, its officers, or directors.