Six tips for evaluating your stem cell culture media

Introduction

Stem cells hold great potential for groundbreaking applications in regenerative medicine and to advance our understanding of human biology. Since their discovery, these cells have served as versatile tools not only for basic research but also with the long-term goal of using them in therapeutic applications. Nonetheless, downstream applications frequently struggle to move forward because of the difficulties researchers face when culturing these cells in the lab with media made in the lab.

Today, there are several commercially available stem cell media available to researchers including classical basal media like DMEM/F12 or MCDB 131 and complete media. A complete medium implies that all of the required components are included in the formulation and that the medium has been optimized and validated with specific cell types and/or specific applications. Components may include small molecules, growth factors, cytokines, insulin, and bovine or human serum. Using pre-validated complete media can eliminate the variability between batches caused by inconsistencies in the lab with home-brew options. 

Whether making media from scratch or using an off-the-shelf complete media, it’s always important to monitor the cells in culture to ensure the media is performing optimally for your specific cells and application. 

We hope these six tips will provide a quick guide for evaluating the performance of your stem cell media.

Tips for Evaluating a Stem Cell Media

1. Pay close attention to cell morphology. Cell morphology is one of the first and simplest ways to evaluate the overall health of the cultures, since changes occurring in stressed or spontaneously differentiating cells can often be observed under the microscope.  
2. Observe proliferation rates. Proliferation and cell growth are also key performance parameters to note. Poor cell proliferation can be a result of nutritional deficiencies or other environmental stresses that can inhibit cell division.  
3. Monitor cell viability. Cell viability after passaging, thawing, and other procedures can be assessed using a trypan blue dye exclusion assay.  
4. Routinely check cell marker expression. Expression of appropriate surface and/or nuclear markers should also be monitored over time, either by flow cytometry or immunocytochemistry.  Remember, however, that for pluripotent stem cell cultures, expression of pluripotency markers does not equate to proof of pluripotency. 
5. Demonstrate pluripotency. Directed differentiation assays are performed in order to show that the cells retain their appropriate differentiating potential in the media.  Spontaneous differentiation (often through embryoid bodies) or directed differentiation to cells representing all three germ lines (endoderm, mesoderm, and ectoderm) are used to demonstrate an embryonic stem cell (ESC) or induced pluripotent stem cell (iPSC) population’s true pluripotency. 
6. Karyotype your cultures. Chromosomal analysis should be assessed with new media formulations or other changes in the culture system to demonstrate that a normal karyotype is retained during long-term culture. 

The tips above represent a baseline to be used when evaluating cell lines, culture systems, and differentiation or other protocols in their ability to support healthy and functional stem cell cultures.  

To learn more about how Captivate Bio can help address your stem cell cultures, visit our product catalog or inquire about our custom media services for making your own formulation.