collagen type I gel will not polymerize

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colI's picture
collagen type I gel will not polymerize


I have a problem with Collagen I 3D culture.

I use the same protocol all the time but for several weeks now I can't make the collagen to polymerize. I use the collagen I solution that contains:

  • L-glutamine or GlutaMAX
  • NaHCO3
  • MEM
  • Hepes
  • Collagen I

I induce the polymerization by putting my chamber-slides in 37C oven. I would expect to see polymerization after 20-30 minutes but instead collagen solution seems to be even more liquid and there is bubbles formation (CO2?).
Also during solution preparation, I can see that collagen solution changes from clear to milky apperance. 

I tried to prepare my own L-glutamine and NaHCO3 but it also didn't work.

I checked the pH and it's neutral as it should be. I prepare everything on ice.

Do you have any ideas what else I might try and what can be the reason for this to happen?