I'm culturing and differentiating C2C12 myoblasts, together with a coworker of mine, and we're testing the effect of two media on myotube formation and differentiation. We've noticed that with the media we've been using to culture and differentiate the cells in until now, causes the cells to form myotubes very nicely (based on morphology). A month a go, we've had contact with a group in France who're also differentiating C2C12 cells, but they use medium that's different from ours in several aspects.
We want to enhance protein synthesis, basically. Where we see a protein enhancement of about 25% after stimulation with several components, they see an enhancement of up to 100% using the same components (in roughly the same protocol)! That's a very big difference. They sent us some photo's of their myotubes, and if we compare them with our own myotubes, we're prone to say ours look 'better' (in the sense that our cultures look as if they're further in the differentiation process than theirs, after the same amount of days).
We tested their media formulation against ours as a start of an attempt to recreate their results. So far, we see that our medium causes the cells to differentiate much faster. However, we also noticed that with their formulation, the cells show much more spontaneous contraction!
My question is: can you say that a culture containing myotubes that shows more contraction than another myotube containing culture is 'more healthy'? In other words, is contraction something you would want if you're performing experiments on myotubes? Can you judge the quality of the tubes based on how much contraction they show?