Opinions on Fermentas DreamTaq Green PCR Master Mix?
Posted 16 November 2009 - 01:02 AM
Posted 28 November 2009 - 11:08 AM
Anyone try the Fermentas DreamTaq Green PCR Master Mix? It's their Taq and whatnot, in a 2x master mix, with the dye also in there, so you can go straight from PCR to gel. (I'm not the sharpest knife in the drawer so the easier it is, the better.) I've been using Promega's GoTaq Green Master Mix with good results, but that stock will start to run low soon, and the biostore at my current institution doesn't sell it. They sell the Fermentas, but it's so inexpensive that I'm a little suspicious. A poster on another thread here warned of their dNTP's, which would obviously be in the master mix...
FYI, for anyone who's interested, I ended up buying some, since this is the least expensive green master mix that my uni's biostore stocks (and my remaining green master mix from Promega "ran out" after an unfortunate incident involving an open tube, gravity, and my pants.) Anyway, I use colored 0.2 ml pcr tubes from DOT since I have a lot of samples to screen and colorcoding groups helps me keep them straight. The Fermentas mix worked fine, *EXCEPT* that the product in my little red tubes turned pink and then had no product on the gel of any sort! The product from the orange, yellow, blue, and purple tubes was fine though. Weird, right? I'm going to write to Fermentas and compain, but... well, I guess you get what you pay for! (Although the Promega GoTaq green master mix is actually about the same price!)
Posted 28 November 2009 - 11:29 AM
Posted 30 November 2009 - 04:13 PM
It sounds to me as if the problem is with the tube manufacturer rather than with Fermentas. Likely the enzyme mix has DMSO or some other solvent that removes dye from the tube. You could try adding neat DMSO to a red tube and see if the solution turns pink when you cycle it. I never use colored tubes, and know of no one who has been working in the field for more than a few months that does.
Actually, it turned out that the problem was with the samples -- same thing happened with the Promega mix, in a different tube color! Something clearly went wrong with those extractions...
As for the colored tubes... well, when they run out I will probably buy regular clear ones, just as a matter of cost. But I like the colored tubes, all my pcr product looks so happy and cheerful in the rack.