Diganosing common challenges when going serum free

So, you want to grow your cells without fetal bovine serum? Be prepared to account for ALL of the myriad roles this golden cow elixir is currently playing in your cell culture.

Here are just a handful of the many roles FBS is playing:

Driving adhesion: Fibronectin and vitronectin are the key proteins found in serum which coat plastic surfaces and help cells stick. Remove serum and many adherent cell types won't attach.

Failure mode: Wonky, raised morphology or floating cells. This commonly reads as a viability issue, when you actually may be really close and just need to start coating your plates with adhesion protein.
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Delivering proliferation signals: Serum contains a complex, variable mixture of growth factors at biologically active concentrations. Different cell types often require different signals.

Failure mode: Slowed growth, usually within a few days.
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Buffering & antioxidant activity: Serum contains a variety of antioxidants which stabilise the culture environment. Without these agents, oxidative stress accumulates.

Failure mode: poor cell health, which worsens if your cells are seeded at lower-than-optimal densities.
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Source of lipids: Many cells need exogenous lipids, and yet lipids are nonexistent in most basal media.

Failure mode: This usually shows up after 3-5 passages, after intracellular stores have been depleted.
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Source of trace elements and hormones: These are present in serum at concentrations that are often important for primary cells and differentiation-sensitive applications.

Failure mode: Cells grow but behave differently, for example unexpected differentiation or altered morphology.
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Provides a carrier protein system: This allows fatty acids, hormones, and other small molecules to be shuttled in and out of cells.

Failure mode: This one usually shows up pretty quickly.
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A serum-free medium that addresses all of these simultaneously, and appropriately for a broad range of cell types is quite challenging to formulate. I’d know!

However, media development can be fairly efficient if you’re focused on one specific cell type. And what I find particularly interesting is that when an adaptation process goes wrong, the failure mode can actually be quite diagnostic if you know what to look for.

Somewhat forwards planning, but I'll be going deeper on all of this in a free seminar scheduled for August. We’ll chat about what a well formulated serum free system actually needs to do, plus how to troubleshoot each of these functions. (Big thanks to Sarah Farrow for suggesting this!)

You can register here: https://lnkd.in/gpJqgbJK