Commercially available media – the hidden pitfalls of proprietary formulations

Liz Stewart, Senior Product Manager at Qkine gives her view on the problems with proprietary media formulations.

During my postdoctoral research in Ophthalmology, I focused on neovascular eye diseases, specializing in the culture of primary retinal and choroidal endothelial cells. To maintain their endothelial phenotype, these cells required a specific medium and I used a bullet kit for this – an expensive but convenient solution. Each 500 ml batch came premeasured, prepackaged, and included all the necessary growth factors and additives needed. Although I didn’t know the exact concentrations, I at least knew what components were included and could omit specific ones for a particular assay. Since joining Qkine, I have come to realize how naïve it was to assume anything about the source or bioactivity of the growth factors and cytokines included in the kit.

Currently, the trend is shifting towards fully proprietary supplements tailored to specific stem cell and organoid types. These can be appealing, particularly for labs starting out with a new stem cell or organoid type, as they are a quick and pre-tested solution which reduces the need for lengthy optimization. This is particularly valuable when working with precious patient samples, where time-consuming protocol development isn’t feasible. Increasingly, however, I hear regrets from labs that have relied on such proprietary media formulations.

What’s in it?

This is the crux of the issue: there’s no recipe, and therefore no scope for refinement or optimization. A customer recently shared concerns with me around the behavior of their adult stem cell derived organoids, which were no longer producing a diverse range of cell types. They were tied into a proprietary media formulation used since the start of their study and were forced to upgrade to a more expensive, and equally proprietary, alternative version from the same supplier to restore differentiation.

Had they optimized a homemade media formulation, they could have adjusted and re-optimized their medium. While this may have taken more time initially, it would have saved costs and offered greater flexibility in the long run.

But really, what is in it?

Commercial media formulations often contain multiple growth factors, but very few companies manufacture these proteins. So where do the growth factors in these formulations come from?

At Qkine, we’re working to transform the recombinant protein industry by emphasizing the importance of growth factor quality and purity. We know that poor-quality growth factors are widespread in the supply chain. By their nature, proprietary formulations lack transparency and there is no way to know the source (e.g. mammalian vs. animal-free), batch, purity, bioactivity, or even the supplier of the growth factors and cytokines – nor when these components change.

Supply and cost

This can be a problem when relying on a specific reagent from a single source, particularly if it is short dated.

A colleague once used a proprietary medium specific to podocytes. While this worked well for the cells, supply issues were frequent. There was only one supplier of the media, making it an extremely risky supply chain. The medium was often out of stock or on back order, and due to its short expiry date, it wasn’t possible to stockpile. When this happened the entire project ground to a halt.

Proprietary media formations are also significantly more expensive than home brew alternatives. In our recent application note ‘Commercial Versus In-House Media: A Comparative Study of Human Induced Pluripotent Stem Cell Maintenance’ we compared the cost of commonly used induced pluripotent stem cell (iPSC) media formulations.

Table 1. Cost per 500 ml for commonly used iPSC media, correct as of August 2025.

Media costs can hinder scalability, such as creating stem cells or organoid banks. There is a growing desire to enable reproducible research across institutes through cell and organoid sharing but this is hindered by the high cost of small-scale protocols reliant on commercial proprietary media.

Home-brewed media

While initial protocol optimization using a home-brewed media formulation may be more time consuming, it may save both time and cost in the long term. Many research groups are happy to publish full protocols for the culture and differentiation of specific stem cell types, which are invaluable resources.

Growth factor selection is a key aspect in media formulation. Qkine growth factors are high-purity, animal origin-free, which undergo lot-to-lot bioactivity testing to ensure consistency. Once optimized, media performance remains consistent.

Qkine has developed differentiation kits which contain all necessary growth factors for specific cell types. These kits are completely transparent, with comprehensive data available for each component. They are designed to offer a bulk discount without locking researchers into proprietary formulations. Each kit is tested and accompanied by a published application note, demonstrating protein suitability and helping researchers kick-start their initial optimization.

When to make the switch?

For researchers looking to move away from proprietary formulations to enable protocol refinement and scalability, the question is: when? There is rarely a good time, especially when resources are limited, but the sooner the switch is made, the less painful it will be in the long run.

More information

In our latest application note ‘Commercial Versus In-House Media: A Comparative Study of Human Induced Pluripotent Stem Cell Maintenance‘ we determine that home made media using Qkine growth factors can be as effective as commercial media formulations for iPSC maintenance.

A recently updated publication from Alessandro Bertero’s lab at the University of Turin, ‘Refined and benchmarked homemade media for cost effective,
weekend-free human pluripotent stem cell culture’. Read the publication and our commentary.