Gel extraction kit...which one is the best? Cheapest? Coolest? lol - (Aug/22/2008 )
I was wondering which gel extraction kits where the best ones out there. I have one from qiagen but I only recover about 50 % of my DNA. I always elute in H20.
Are there cheaper, better ones out there?
Also, we dont have miniprep kits in the lab, we use phenol-choloform or something like that which takes a long time? Id like to buy a miniprep kit theyre so easy to work with but I think the qiagen one is pretty expensive right? Or maybe using the other method one gets better results?
I tried several different gel extraction kits and none of them really work well. I normally start with 5 µg plasmid DNA, digest it and then isolate it from a gel to get approx. 1 µg back. I haven't found one that is really good. So far I get the best results when using a kit from Invitrogen which requires 50µl elution volume. Since this is way too much, I concentrate it afterwards with a Zymo kit to 6-10µl. Zymo kits are OK too, and the kits are cheap. They are approx. $1 per reaction.
Qiagen is def. expensive and for Miniprep kits, they are a lot of companies out there. Most of them offer test kits. I know that Zymo does. I would just call a bunch of companies, have them send you test kits. That should help you for a while. And then you can check out, which one is the cheapest.
The elution volume depends on the type of column used, if you want a smaller elute volume then use a low elution column. That is all you need do to concentrate without using another kit.
There is a gel extraction kit from Omega Bio-tek that has good recovery rates. Their kit only uses 1 volume binding buffer as well, this helps to concentrate the DNA too. They are cheaper than Qiagen too.
For Minipreps, I really like Zymo's Zyppy EndoFree kit. Basically, you can process a sample in about 10-15 minutes, and get a really clean, endotoxin -free miniprep that I've used for transfection into human tumor cells without doing Phenol/Chloroform or other extraction/precipitations. I use water heated to 60'c to elute, and use 50 ul once, add a fresh 50ul, repeat the spin, and then run the pooled eluate (~100ul) back through the column one more time...seems to increase the yield. Afterward I use the spinvac to bring the volume down to ~10ul of a fairly concentrated supercoiled plasmid. As for your 'coolest' request, I find that the color changing buffers provided with this kit which let you know when your alkaline lysis is neutralized is very helpful too
From there, I use Promega's Wizard SV Gel/PCR cleanup kit recover linearized plasmids from an agarose gel. I do basically the same elution scheme (50ul+50ul-->100ul) as with the Zyppy and get ~75% recovery.
Both kits are quite inexpensive relative to the Qiagen and Invitrogen analogs, and like UGA80 said you can ask the companies for a 'trial-package' to see if these kits will work for you. The linked Zymo page above has a link to their form for free-trial version of the Zyppy kit. Cheers-JAH
I have tried Quiagen and Roche. Roche kit was definitely gave much better yield for extracting DNA from agarose gel. But ensure for the maximum DNA size as this kit is mainly meant for PCR purification.