Dear Evoldir, I promise many of you I would post the replies to my query about alternative DNA extraction Kits for plants. I did received some very useful replies and they are post anonymously bellow. However, given there didn't seem to be enough evidence in direct comparisons I went ahead and order samples of a few kits to compare them myself. We tried DNEasy from Qiagen, Nucleospin from Macherey-Nagel, EZNA by Omega BioTek (sold by VWR), and the ChargeSwitch from Invitrogen (magnetic-bead based). Bear in mind that we were using these kits in Arabidopsis which is a fairly benevolent plant to extract DNA, some of these might work quite differently in species that have lots of secondary compounds. Still, we found the same as some of the repliers told me: They all seem to work equally well. We amplified PCR products and digest all samples with the same efficiency. The Nucleospin kit gave the highest yield but it is as expensive as the Qiagen, the EZNA is the cheapest and has comparable yields with the Qiagen. However, we were quite impressed with the ChargeSwitch. We haven't use the magnetic beads before, and they seem much easier to do, and harder to have students mess up the protocol. It also requires less centrifugation, which can be a plus in some situations. There are other companies that have magnetic beads kits now (including the EZNA) but we have not tried their kits. They might be worth giving a try. Some repliers suggest that DNA extracted with different methods might have different shelf-life. This can be an important factor in some situations, but at the moment we can't comment on that. Hope this is useful! And sorry it took me so long! Paula Replies: "I used to work with Qiagen's kit, but recently switched to EZNA's kit for two reasons. First it was a price issue, EZNA's kit cots about 1/4 to 1/3 or Qiagen. Second, the company marketing the EZNA kit here in Sweden were pretty aggressive and directly targeted Qiagen users (they used to represent Qiagen but Qiagen decided to take over the distribution themselves). The end result is that our local chemistry store at the university now always stock the EZNA kit, meaning that we can always get a new kit within minutes without having to order and wait for a week or so to get it. We haven't experienced any noticeable drop in DNA quality with EZNAs kit, although I think the yield for the EZNA kit might be a little lower (10-15% or so) than Qiagen's kit. We've also switched over to EZNA's PCR purifying kit, where we also used to work with Qiagen's kit. Again the performance is about the same." ------- " I have compared both kits. Some of my students are able to get very good results witht he EZNA kits. The other half have prefered to continue with the Qiaquick kits. The EZNA kits do not have the same efficiency as the Qiaquick kits. So if you are working with limited DNA samples they may not be so good for you. In addition they don't seem to purify as well as the Qiaquick. However if you have lots of DNA and a robust PCR protocol the EZNA kits would be fine." ------ "The best method we used was after extraction perform an ethanol precipitation then the EZNA columns and that improves their purification ability enormously we did not figure a way to increase the efficiancy of the recovery except to concentrate the DNA afterwards." ----- "Depending on the plant, you might be able to dispense with kits entirely. We do a high-throughput (2 96 well plates at a time, takes about 3 hours) CTAB/chloroform extraction with Mimulus that produces plentiful DNA of fine quality for sequencing and genotyping. It's a little fiddly and you need good equipment (a Genogrinder or some other way to grind the tissue in 96well format, a deep bucket rotor centrifuge, a Matrix 1250 extended tip pipettor -- the same stuff Qiagen recommends for it's 96-well plant DNEasy kits), but it is essentially free after that. We've had success with some other taxa using this protocol or variations (Silene, Solanum, leaf-eating beetles) but some things with high secondaries (oaks, composites) yield lots of DNA but also end up with stuff coming through that inhibits PCR. Anyway, something to think about it you are looking at extracting thousands of samples on a regular basis." ---- "One of my friends uses the wizard kits (I can get the brand name if you need). He doesn't think the DNA comes out as clean as with Qiagen kits but he thinks he get a higher yield from them." ----- "Most of these kits are largely the same. If you would really like to save money, please see the attached protocol that we published this month - we compared it directly to Qiagen. http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1471-8286.2006.01549.x However please note the typo on page 3 - the grind buffer should be 320ul of homogenization buffer and 80ul of lysis buffer (not 320 ul of lysis buffer)." ------ "Saw your EvolDir post. We've been using Viogene (Sunnyvale, CA) kits for several years now. I found an order form from 2005, and a box of 50 extractions was 65 USD. I used these kits for 80% of my Arabidopsis work, and I had good luck with sequencing and genotyping (8 microsat loci). Plus, I never standardized the amount of leaf material I used or the concentration of extracted DNAs, so these kits seem robust" ----- "Here in the lab we no longer use the DNeasy kits from Qiagen. We use the Nucleospin Plant 96 by Macherey-Nagel to extract DNA from seaweeds and it works very fine (as fine as Qiagen). We changed because MN allowed us a better discount than Qiagen so that it results cheaper. We have very good results for sequencing (chloro, mitochondrial or nuclear DNA) and genotyping (microsatellites). The principle of the kit is the same as DNeasy. https://www.macherey-nagel.com/web%5CMN-WEB-BioKatalog.nsf/web/PLANT96/$File /Genomic_DNA_Plant_8-96_R01.pdf I tried the EZNA kits from VWR for tissue (mollusk) but it did not yield anything. There are very cheap but you should be aware that I have been told the DNA extracts have a much shorter lifespan than with Qiagen or MN. But I have not tested that for plants." ----- "I haven't used the VWR kits but I just switched to one from IDLabs for similar reasons (price, also about 1/4) and we're just as happy with it as the Qiagen kit and the customer service of the company is fantastic. They are located in London, Ontario but they ship internationally. Here is the link, http://www.idlabs.com/product/ They have separate kits for plants, animals, blood, bacteria" ---- Dr. Paula X. Kover University of Manchester Faculty of Life Sciences Michael Smith Building - room C.1261 tel.:(0)161- 275 1550 "Paula X. Kover"