I prefer HPLC too, and am currently using a Waters LC for all my protein purifications. I have also used a Dionex Bio-LC in the past, which does have non-corroding PEEK pump heads. It was a great system.
Peter On 2/14/07 8:18 PM, "Daniel Anderson" <[EMAIL PROTECTED]> wrote: > It still seems to me strange that Bio-Rad would build a machine that can > reach pressures suitable for reverse-phase chromatography, but then not > include software control for gradual pump acceleration. I tried to > communicate to BioRad corporate suits that many HPLC columns are too > fragile for abrupt pump acceleration, but it was like speaking Swahili. > > Having typed that, I'm not up to date with the latest DuoFlow software. > > For HPLC, I'm still very fond of Waters pumps and their gentle handling of > columns. I tried to communicate to Waters corporate suits that what the > academic world could use is their Breeze system with non-corroding pump > heads, but it was like speaking Swahili. > > (FPLC is a trademark. The marketing hype has been so effective that many > people think that FPLC is a method.) > > -Dan > > On Wed, 14 Feb 2007, William Clemons wrote: > >> In my old lab everyone was slowly converting to Bio-rad for >> chromatography. We had an Akta and subsequently bought two Bio-rad >> DuoFlow. I actually never made the conversion then but those that had >> didn't want to use the Akta anymore. >> >> Upon starting my own lab I got quotes for both an Akta and a DuoFlow >> and the cost difference was striking. As Tamir said, the DuoFlow >> really is plug and play and you can build up the system you want so >> just buying the basic may not get you far but relatively easily you >> can get all of the features of a mid-range Akta (mutiple buffer >> valves, column valves, multiwavelength (4)). I should add that in all >> my interaction with equipment reps at GE Healthcare I generally came >> away with the feeling that they don't care that much about academics. >> They have a real air of superiority which is enough for me to not buy >> from them (although I get all my columns from them!). >> >> There are a few downsides to the DuoFlow. The software is not as nice >> as that for the Akta but it is fairly easy to train on and all of my >> people have gotten along fairly easily with it. The pumps for the >> standard DuoFlow are rated for much higher pressures than we >> biochemists typically use so sometimes they can struggle with >> pressures below 40 PSI. We got around this by adding a pressure >> inducer past the pump and have had no problems since. The only other >> downside that I'd mention is that the service reps aren't very well >> trained so this may not be the best system if it is the first time >> you've seen an FPLC. We had a Service Rep come in who forgot to turn >> off the pump after his test runs. This happened on a Friday and no >> one noticed the pump was running until the following Tuesday. This >> killed the pump but they quickly came and replaced all the parts and >> we haven't had a problem since. >> >> My final point is that Bio-rad is really great (at least here in LA) >> with academics and we were able to bundle in all of our protein gel >> parts, DNA gel parts, PCR machines, Gel Doc etc for less than the >> quote for the equivalent Akta. In fact, I just had a second Duo-Flow >> installed yesterday and was able to again bundle in a lot more >> equipment for my slowly growing lab. Bio-Rad isn't perfect but they >> get at least a B+ from me for general support and in the end my >> experience continues to be a positive one. It is probably the best >> purchasing experience I had in my start up and the only one I haven't >> had some major regret on. >> >> Just my 2 cents, >> >> Bil >> >> On Feb 14, 2007, at 8:41 AM, Tamir Gonen wrote: >> >>> I beg to differ. >>> >>> I have been an AKTA explorer user for about 5 years and switched to >>> DuoFlow about 4 yrs ago and now have one in my own lab. The BioRad >>> DuoFlow is awesome. It never ever breaks. I never had any problems >>> with this machine at all, it takes any column (pharmacia or >>> otherwise) given the right adapters. The AKTA are really cumbersome >>> and complicated to use and teach on - its all inside a big black >>> box that looks (and feels) like a tank, while the DuoFlow has a >>> really simple design, and is basically "plug and play". >>> >>> The AKTA is really good for analytical applications when you have >>> very small amounts of your protein and of course you can detect >>> multiple wave lengths at a time (you can add special unit for multi >>> wavelengths on the biorad). The DuoFlow struggles with very small >>> protein concentrations (<0.05mg/ml) and the void volume on its >>> tubing further dilutes the sample. If you know what you are doing, >>> it is easy to optimize the setup in such a way that you minimize >>> the void volume on the DuoFlow. >>> >>> Finally, the AKTA has an in line filter which always gets clogged >>> up when you have buffer with detergent. The DuoFlow does not have a >>> filter at all which means if your students and postdocs are not >>> careful, the filters in the column will get clogged. But all you >>> need to do is filter your sample prior to injection. >>> >>> BioRad service is not so great but if you take care of your machine >>> you really dont need to worry. It is really robust. Plus, for the >>> price of an explorer you could buy two top-of-the-line DuoFlow >>> systems together with columns. >>> >>> Tamir. >>> >>> >>> ______________________ >>> Dr Tamir Gonen >>> >>> Department of Biochemistry >>> Box 357350 >>> University of Washington >>> Seattle, WA 98195 >>> >>> Tel: (206) 616 7565 (Office) >>> (206) 616 8529 (Lab) >>> Fax: (206) 685 1792 >>> [EMAIL PROTECTED] >>> >>> http://faculty.washington.edu/tgonen/ >>> >>> >>> >>> >>> On Feb 14, 2007, at 8:19 AM, Frank Lee wrote: >>> >>>> >>>> Dear all, >>>> >>>> Thanks a lot for all the feedbacks on AKTA prime. They are so >>>> helpful that I have abandoned the idea of buying one. Now it is a >>>> choice between AKTA FPLC and Bio-rad DuoFlow. I heard that DuoFlow >>>> is not as robust as AKTA and that its parts break down often. The >>>> question is whether quality difference is worth price difference (~ >>>> $10K). Any feebacks on DuoFlow would be highly appreciated! >>>> >>>> Best, >>>> Frank >>>> >>>> Food fight? Enjoy some healthy debate >>>> in the Yahoo! Answers Food & Drink Q&A. >>> >> >> ************************************ >> Bil Clemons, PhD >> Assistant Professor of Chemistry >> Caltech >> 157 Broad Center >> MC 114-96 >> Pasadena, CA 91125 >> (626) 395-1796 >> [EMAIL PROTECTED] >> ************************************ >> >> >>
