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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Dear Lena, John, and others,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I'm Vlad, in charge of the easiGlow<sup>TM</sup> and cryo-EM supplies here at Ted Pella. Since I took over the easiGlow<sup> </sup>two years ago, I’ve been hearing occasional but persistent requests for an oil-free pump. Seeing Lena’s post, thought I would share the following with all current and future easiGlow users.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>On oil in the GD4 pump</b>:<o:p></o:p></p><p class=MsoNormal>The GD4 pump has a special valve to prevent any backflow of oil into the instrument, so that is not an issue. Some people still want "no oil in the room", which is a bit OCD, considering how well ventilated modern preparation rooms are, but would perhaps be a concern if the pump did generate a significant amount of oil. However, it would do that only after long continuous operation, when the pump becomes warm (and it never gets even close to that with the easiGlow). And even then, there's a special Oil Mist Filter, that blue cylindrical thing you see on top of the pump. We have at least one easiGlow unit in most or all top cryo-EM labs here in the US and Canada, and to our knowledge, all are operated with the standard GD4 pump.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>On oil-free pump alternatives for the easiGlow</b>:<o:p></o:p></p><p class=MsoNormal>The easiGlow has steep requirements to the vacuum pump, that's one of the reasons it is so robust and reliable, giving you highly reproducible results, quickly. The pump must have what is called "classic progressive pump down curve", in addition to being able to pump down fast, and it must hold the vacuum very stably. We tested many pumps before finally arriving at this GD4, which has proved to be as good as a major brand name pump selling for 3x the price. An oil-free pump of comparable performance would cost upwards of $5,000 US and be quite large (thus the Edwards XDS6i will likely work, although we have not tested it here). That's why 10 years ago when the easiGlow<sup> </sup>was first introduced we dismissed that option. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Having said all that, we are now in fact considering introducing an Oil-Free Pump, as a purchase or upgrade option. The reason is that some customers still want that, whether that is justified or not, and I feel now that the price is not much of an issue for such customers. We can of course introduce such pump only after a very thorough testing, as we are going to fully support the modified setup. So this may take a little while. Meanwhile of course anyone is free to try use their easiGlow with any pump they choose (and I would be interested in any feedback), but we at this point can only fully support it with the GD4.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>@John on the edge of the bell jar being easy to chip</b>:<o:p></o:p></p><p class=MsoNormal>That is absolutely correct. I always advise folks to use both hands when putting the chamber back in place, and use the free fingers to securely center it. But of course things can happen in a multi-user facility, and after hearing over the phone a couple times how the chamber edge “chipped itself”, I included among the highly recommended accessories for new buyers a protective L-shaped rubber gasket that goes around to cover the entire edge. The gasket is $76.80, but we are right now making it part of the standard product, free of charge.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Best wishes,<o:p></o:p></p><p class=MsoNormal>Vlad<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Vlad Speransky, PhD<o:p></o:p></p><p class=MsoNormal>Life Sciences Product Specialist<o:p></o:p></p><p class=MsoNormal>Ted Pella, Inc.<o:p></o:p></p><p class=MsoNormal><a href="http://www.tedpella.com/"><span style='color:windowtext'>http://www.tedpella.com/</span></a> <o:p></o:p></p><p class=MsoNormal>530-243-2200 ext. 266<o:p></o:p></p><p class=MsoNormal>Cell 530-768-3953<o:p></o:p></p><p class=MsoNormal><a href="mailto:vlad_speransky@tedpella.com"><span style='color:windowtext'>vlad_speransky@tedpella.com</span></a><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='mso-element:para-border-div;border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 1.0pt 0in'><p class=MsoNormal style='border:none;padding:0in'><o:p> </o:p></p></div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> 3dem [mailto:3dem-bounces@ncmir.ucsd.edu] <b>On Behalf Of </b>John Rubinstein<br><b>Sent:</b> Thursday, March 01, 2018 6:28 PM<br><b>To:</b> Lena Maria Muckenfuss<br><b>Cc:</b> 3dem@ncmir.ucsd.edu<br><b>Subject:</b> Re: [3dem] Vacuum pump for glow discharge purposes<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Dear Lena,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>We’ve used the Pelco easiGLOW extensively with the standard pump for the past four or five years. It works nicely and I think it is great system. My only criticism is that if users aren’t careful it is easy to chip the bottom edge of the bell jar when removing it or putting it in place, which makes the bell jar incapable of making a seal (I think a replacement bell jar is just a few hundred dollars).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Best,<o:p></o:p></p><p class=MsoNormal>John<o:p></o:p></p><p class=MsoNormal><span style='color:black'>-- <o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>John Rubinstein<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>Molecular Medicine Program<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>The Hospital for Sick Children Research Institute<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>686 Bay Street, Rm. 20-9705<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>Toronto, ON<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>Canada<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>M5G 0A4<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>Tel: (+001) 416-813-7255<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'>Fax: (+001) 416-813-5022<o:p></o:p></span></p><p class=MsoNormal><span style='color:black'><a href="http://www.rubinsteinlab.org">www.rubinsteinlab.org</a><o:p></o:p></span></p><p class=MsoNormal><br><br><o:p></o:p></p><p class=MsoNormal>On Mar 1, 2018, at 9:29 AM, Lena Maria Muckenfuss <<a href="mailto:l.muckenfuss@bioc.uzh.ch">l.muckenfuss@bioc.uzh.ch</a>> wrote:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Dear list members, <br><br>we are about to purchase a "easiGlow” glow discharge system from PELCO for single-particle cryo-EM purposes and were wondering if anyone has experience with the supplied GD4 rotary vacuum pump, which is not oil-free. Are the concerns of oil leaking into the chamber true and is it worth purchasing an oil-free pump (e.g. Edwards XDS6i) instead? We would be very thankful about any experience you are willing to share. <br><br>Best wishes, <br><br>Lena<br><br>----------------------------------------------<br>Lena M. Muckenfuss<br>PhD student<br>Group of Prof. Martin Jinek<br>University of Zurich <br>Department of Biochemistry<br>Winterthurerstr. 190<br>CH-8057 Zurich<br>+41 44 635 555 | 44-L-82<br>----------------------------------------------<br><br>_______________________________________________<br>3dem mailing list<br><a href="mailto:3dem@ncmir.ucsd.edu">3dem@ncmir.ucsd.edu</a><br><a href="https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem">https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem</a><o:p></o:p></p></div></body></html>