Detecting (and avoiding) foam in tubes

  1. I know how much is in the tube since I add the lysis buffer in the previous step. However, I do not know the ratio between foam and actual liquid.
  2. The liquid amount is calculated from what I add before. E.g. the pellet is stored in Ethanol until extraction. I remove the Ethanol with TADM activated and discard the tip when it is clogged. I then add XX uL of lysis buffer and after incubation I remove XX uL - 200 uL of lysate so I have a bit of room. Therefore aspirating as little under the liquid level is desired to avoid the pellet.

BUT: Your suggestion might actually work out fine! But before trying it, I will check out silica-antifoams. They look like a really promising solution, since they seem to be effective at a concentration as low as 30 ppm, which should have no effect on my samples. I’ll keep you updated about this, since it might be interesting to others as well.

So, I got Silicone Antifoam solution from Carl Roth and it effectively inhibits all formation of foam at a final concentration of 100 ppm :slight_smile: Problem solved.

Will perform a testrun tomorrow, but am quite confident that this will work out fine!


Performed my tests and there was no foam formation (that I could not remove with quick centrifugation) whatever I did. Bead-beating, high-rpm incubation…

If someone encounters this problem I can highly recommend silicon defoamer :slight_smile: