Issue with homemade PFA

Alex_BainsLab

I have read several reports where homemade PFA has been cited as the cause of unreliable polymerisation of the hydrogels. I have also had some problems with homemade PFA that seem to be resolved by ensuring the pH of the PFA is >7. I believe that a low pH could inhibit the thermal initiator but I am not sure. Could this be the case? Or could excess protonation inhibit cross-linking directly?

EmileHashem

Make sure your 10X PFA has a pH of 7.4 and you won't have problems.

I have made 4 large batches of the Hydrogel solution, used it fresh and thawed, and always get a good hydrogel.

Most important is to make sure you have no oxygen touching the hydrogel when you are polymerizing. I either fill up the tube all the way with solution, or I use "Private Preserve" a mixture of heavy gasses that I use to preserve my red wine after I have opened a bottle

Clarifier

EmileHashem said:

Make sure your 10X PFA has a pH of 7.4 and you won't have problems.

The protocol lists 16% PFA....@EmileHashem was 10X a mistake, or have you modified things?

Genesprite

We make a home made 10% PFA and adjust the PH to 7.4, we then use this to make the 4% PFA in the hydrogel mix. I've only made a couple of batches, but it's been fine. I also either fill a 15 ml conical to the top, or part way and add a layer of oil. I heard that peanut oil works, but all I had on hand was sunflower oil. It worked great!