I have recently moved departments to one that does very little molecular biology. Having always used ethidium bromide, I went and set up my laboratory using it as the stain of choice for producing DNA gels. However I am sharing a large laboratory space with two other groups, one of which members have complained that I am using EtBr and should have warned everyone that there is a new hazard in the lab (even though they don’t have any contact with it). Turns out they use Sybr Green. Are they overreacting? Or am I just so used to using this most days for the last 10 years that I underestimate potential hazard that it represents? Sure I always use gloves and wear a labcoat and dispose of the gels/solutions carefully in accordance to the safety guidelines (if course!) but should I be setting up my lab with a “safer” however, more expensive alternative?
In my previous department everyone was using EtBr and one of the group leaders even infamously said that he “would bath his children in it”. However, it can intercalate into DNA (insert itself into DNA molecules) and as such is labeled as a “potential mutagen”.
Based on the Ames test it has been shown to be a mutagen but is not a known carcinogen and it's effects on humans is unknown. One alternative Sybr Green, is a much weaker mutagen but is more toxic (http://www.sciencedirect.com/science/article/pii/S1383571898001727) and more readily enters living cells vs EtBr. The costs are also a potential concern, these alternatives to ethidium bromide are much more expensive and when you are starting up with a limited budget with students who are likely to be running many gels, it becomes a significant expense. Ignoring the cost and the potential risk of EtBr use, the main reason I would switch to something like Sybr Green would be the increased sensitivity. It can detect much lower levels/quantities of DNA vs EtBr.
What to do? I think, for now, stick with EtBr but insure that all the students that come to the lab take care and follow all the precautions required (as they should with all chemicals they work with in the laboratory) to ensure they don't risk contaminating any laboratory space and look to switching to a more sensitive alternative once I get that first big grant.
So better get grant writing....
