Choosing the Right hPSC Medium – Points to Consider

Today, when it comes to choosing which human pluripotent stem cell (hPSC) medium to use for your stem cell cultures, scientists and clinicians have many choices. You may be asking yourself “How do I know which media I should be using?” or “How do I choose the right media for me?”

^{This article is posted on our Science Snippets Blog} 

Application

When reviewing the various options available in hPSC culture media, researchers often wonder if they really need a defined, serum-free, xeno-free medium. If your research is translational, or at some point you think it may end up being translational, your media requirements will likely be dictated by your application, since using defined, xeno-free media produced under cGMP standards can be critical for FDA approval. (In addition, choosing a formulation with a registered FDA Drug Master File (DMF) will further hasten the time to final FDA sign-off.)

But what about for stem cells used in basic, non-translational research? The truth is – if you’re doing non-translational research, this type of definition and purity may not be completely necessary in the same way it is when working within the regulatory framework of cells intended for downstream clinical use. However, simply using the scope of “clinical vs non-clinical” to filter media choices doesn’t take into consideration the benefits the media may have for cell cultures in general. Compared to lab-made “homebrew” media, using a defined, serum- and xeno-free medium drastically decreases the variability from batch-to-batch, while increasing the overall reproducibility of your experiments – ultimately saving time and energy so that you can focus on your experiments and your more meaningful lab work. After all, if a defined, xeno-free medium exists that is comparable in cost and keeps your hPSCs proliferating and undifferentiated, then why not use it?

Substrates

Another point to consider when evaluating media is the substrate(s) you are currently using to support your cultures. There are numerous substrate options and variations for hPSC culture, including MEFs, HFFs, Matrigel, Vitronectin, multiple Laminins, ECM protein combinations, and fully synthetic surfaces. However, since many of the different substrates secrete or express different attachment and growth-promoting proteins, we can’t expect that every available medium will effectively match with every substrate option to fully support hPSC attachment and survival. Because of this, it is important to check that the media you are choosing can be matched with your particular substrate. You can generally find this information in the suggested protocol for the medium, the product information online, or by speaking with a technical expert. Additionally, depending on the substrate used, your choice of passaging method (enzymatic vs. non-enzymatic, colony “clumps” vs. single cell) may also vary – so it is important to verify that your choice of media/substrate/passaging method will work well together.

Compatibility

Consider the overall usefulness of each medium for a diverse range of experiments and applications. Many researchers today are performing groundbreaking work on a variety of concepts, including cellular reprogramming, high-throughput screening, cellular differentiation, and large-scale expansion and scale-up for translational therapeutic use. Just as you need to consider your substrate, it is important to also think about which types of projects the cultures may be used for, and then verify that your medium choice will be appropriate.

For many projects, the media’s growth factor concentration is a critical component that can greatly impact experimental results. While some available hPSC media require high amounts of certain growth factors (specifically bFGF) to maintain undifferentiated cells, not all do – and it is much easier to add growth factors to a media (if necessary) than it is to remove them once in solution. If you need to adjust growth factor concentrations for your cultures, look for a medium that has a growth factor-free version so that cells can be seamlessly transitioned between conditions without additional adaptation or adjustment periods.

Ease-of-use

Finally, overall ease-of-use and schedule flexibility are important factors to consider. Media that comes to you fully quality controlled, performance-validated, and in a ready-to-use format frees up valuable time for you to focus on your actual work, rather than preparing, diluting, or validating your media. As most researchers know, demanding schedules and constant deadlines tend to leave little free-time away from the bench and office. To address this, some hPSC media have shown that their formulations can allow researchers to periodically skip routine culture feedings or culture hPSCs in a “weekend-free” manner. (Note: although this technique can come in very handy, it is important to be aware that such feeding schedules may not be the best option for every cell line or experiment, and you should verify that skipping feedings is not negatively impacting your cultures over time.)

NutriStem^® hPSC XF Medium – Reliable. Flexible. Trusted.

The above considerations are just a few of many points to think about when choosing a medium to use for your hPSC cultures. Not all media are created equally, and some are likely be better suited than others for certain purposes and culture needs. However, NutriStem^® hPSC XF Medium has been designed to be an optimal and flexible medium for basic to translational research, and everything in between.

Here are some of the highlights of NutriStem^® hPSC XF Medium:

• Defined, xeno-free, and serum-free medium designed for experimental reproducibility and minimal lot-to-lot variation
• Specific and complete Drug Master File (DMF) registered with the FDA to better enable clinical translation
• Supplied as an easy-to-use, all-in-one solution – no mixing or diluting required
• Available in a growth factor-free version and other customizable options, allowing for optimization based on specific experimental or laboratory needs
• Supports efficient attachment, thawing, and passaging, which minimizes the need for supplementation with ROCK inhibitors for cell survival
• Successfully used with multiple substrates
• Including: MEFs, HFFs, Matrigel, Vitronectin, LaminStem (Laminin-521), Laminin-511, Geltrex
• Compatible with multiple enzymes
• Including: Accutase, Collagenase IV, Dispase, EDTA, recombinant trypsin-EDTA
• Supports both standard colony/clump passaging as well as single cell passaging methods
• Supports cellular reprogramming and gene-editing
• Amenable to a flexible feeding schedule, including weekend-free feeding when paired with Laminin-521
• Contains low basal levels of growth factors (including bFGF), allowing for additional supplementation if needed

Have any questions or need more info? Please contact us at sartorius.com.