02 May 2009

Sucrose and Animal Bone Char

Sucrose (refined table sugar) is a common chemical used in the lab. It can be used in media for growing cells, but more commonly it is used to make solutions denser. I have used it instead of glycerol in Laemmli sample buffer for SDS-PAGE gels.

As many of you may know, the reason why most table sugar at the grocery store is white is because it is filtered through burned cattle bones. You may think that this could possibly be different in the lab. While you probably will not see turbinado sucrose in the supply cabinet anytime soon (if ever), there could always be the possibility that some chemical can be used for lab-grade sucrose that would not be acceptable for food-grade sucrose.. According to my cursory research this is not the case.

Bone char is not only a concern for vegans, but also for many protein biologists. A previous lab I worked in did a lot of sucrose step-gradients, and the primary investigators there were very concerned about protein contamination, and the bone char issue was something they discovered and had to deal with. Some of them had been working on prions, and because of the difficulties of prion decontamination they had also been looking into mammal-free supplies.

A message to Sigma-Aldrich garnered this reply from Harry Dapron, Technical Service Senior Scientist:

Sigma-Aldrich does not make this product and so I contacted our supplier of this product. They did confirm that it is bleached/filtered using bone char. I cannot speak of any other product because other sugars that you have referred to in general may come from several different suppliers.
A question to Fisher got a similar response. I did learn that product 4005 from J.T. Baker is NOT filtered with bone char. It seems like the higher purity versions may be more likely to be animal-free. If anyone finds out any more brands that are animal-free or not, let me know. I'm working on a database or chart that has all the info.

I wonder though if other chemicals are refined this way. I don't think any salts would be, as grocery-store salt is not. But would dextrose? Further research is clearly needed.