Help with Ethidium Bromide Contamination - (Nov/15/2011 )

Hey guys. I worked in a biochem lab last year and I had to use etbr for a couple of DNA gels that I did. I was told to throw out my gloves immediately after handling my DNA gel which I always did, but I while I was handling the gel I would use the same gloves to open the UV box, use a lab computer to print the image (the keyboard was saran wrapped and everyone had to wear gloves while using it) and open the refrigerator door (to store the gel). Was this correct or should I have changed my gloves each time I came in contact with gel? What worries me is that the etbr residue on these pieces of equiipment could have been transferred when other people touched the equioment with their gloves. The problem is that my lab is small and the members of my lab must rely on other labs to use equipment and when they go to these labs they walk through communal areas with their used gloves on. I fear that the etbr may be transferred to doorknobs and such that are later touched by non-lab students, with their bare hands. I dont want anyone to be affected by a fault of my own. Am I being paranoid? I hope I am because the thought of unintentionally hurting others really scares me. I got into science to help others not hurt them.

It is bad practice to touch anything such as doorknobs etc. with gloved hands - not just for the potential to contaminate others, but also for the potential to contaminate your work!

There are a number of techniques you (and others in your lab) can use to get around this - you can (and should) have samples on a tray, keep ones for EtBr separate and label them properly if you are worried about spreading it. You can then carry this with one gloved hand, and keep the other ungloved. You can also handle most gels with a single hand, so that the other hand can be used to manipulate doors etc., and you won't spread contaminants around.

Having said that, there is little evidence that EtBr is as bad as it is sometimes made out to be. Yes, if binds (well, intercalates, but we won't go into that) the DNA/RNA but it is (used to be?) used as a routine treatment for sleeping sickness and other trypansomiasis in cattle for many years with no reported increase in tumours or birth defects. Cattle are dosed at about 1mg/kg of body weight - typically in the lab you are using it in the ug/L range.

Have a look here: http://bitesizebio.com/articles/ethidium-bromide-a-reality-check/

Thanks for the info, really appreciated. It does put me a bit more at ease. I hope i can move on from this. Its been consuming me for awhile now so hopefully I can move on from it.

Does anyone else have any takes on this?

Hey
We once checked a DNA-electrophorese-room for contamination of etbr with a strong UV-lamp. The view was dramatic! Walls and wastebins were glooming.
Maybe you can check with a UV-lamp for severity of contamination?
Good luck

fysio lab on Fri Nov 18 12:53:19 2011 said:

RJ1989 on Thu Nov 17 11:38:47 2011 said: