Re: [ccp4bb] Hanging vs. Sitting
Hi, >From the experiance of mine I can tell you that the crystal size sometimes >matters between these two methods. Hanging drop may yield bigger crystals than >sitting drop, that may be due to the evaporation rate(surface area). Hanging >drop allow us to set different protocols also like free interface diffusion, >area covered by the drp etc. These informations are gained purely by experiance. cheers Deb On Thu, 30 Apr 2009 20:40:35 +0530 wrote >I have noticed that a significant majority of crystallizations are done in >hanging- rather than sitting-drop configuration, and considering the >significant extra labor involved in hanging drops, can only understand this >preference as a historical bias. I understand that sometimes one technique >works and not the other, but all things being equal, why is hanging drop >still "hanging around?" Any insights appreciated... > >Jacob Keller > >*** >Jacob Pearson Keller >Northwestern University >Medical Scientist Training Program >Dallos Laboratory >F. Searle 1-240 >2240 Campus Drive >Evanston IL 60208 >lab: 847.491.2438 >cel: 773.608.9185 >email: j-kell...@northwestern.edu >*** >
[ccp4bb] Call for proposals for biodeuteration [SEC=UNCLASSIFIED]
The (Australian) National Deuteration Facility has issued a call for proposals for protein and DNA deuteration services. The deadline for this first call is May 8, 2009. Deuteration may be necessary or desirable for: * Neutron crystallography * Neutron scattering (e.g. SANS, neutron reflectrometry) * NMR * Other purposes with scientific merit Deuteration services are available for proteins, DNA, or other molecules produced using bacterial fermentation in D2O, using deuterated precursors if necessary. Deuteration via chemical synthesis is not included in this call, although informal expressions of interest are always welcome, and recommended where development lead times might be long. For more information, please see www.ansto.gov.au/ndf This call for deuteration proposals is part of a general call for neutron facility proposals at ANSTO. See http://www.ansto.gov.au/research/bragg_institute/users Sincerely, Dr Anthony Duff ANSTO Bldg 21 PMB 1, Menai NSW 2234 Telephone: 02 9717 3493 Mobile: 043 189 1076
Re: [ccp4bb] Hanging vs. Sitting
Hi, I beg to differ. Evaporation rates change dramatically between a drop lying on a flat surface open to air flow; a drop lying in a depression; and a drop lying in a depression with some reservoir solution next to it. We're talking seconds to minutes. So especially when using robotics to set up lots of drops, you might find increased precipitation (or nucleation?) events in hanging drops -- but also less repeatable experiments. As for visualisation: a proper drop shape (e.g. as used in the SwissCi MRC or 3-drop plates) can make a big difference; certainly those are superior to average hanging drop, I argue. (Whatever "superior" means.) phx Bostjan Kobe wrote: There is really not much difference in terms of setup between hanging and sitting drop, especially if the drops are set up on tape. Visualization is also usually easier with hanging drops. Bostjan On 1/05/09 1:37 AM, "Poul Nissen" wrote: We often find results to be very different between hanging and sitting drops (equilibration kinetics for one may be the explanation). Then there's the good thing of hanging drops that crystals rarely stick to the surface of the support facilitating the mounting procedure, in particular for fragile crystals. All in all we much prefer hanging drops for our membrane proteins - the bottle neck is not in the extra few minutes for set-up, but in the months it takes to produce the protein. Poul On 30/04/2009, at 16.45, Jacob Keller wrote: I have noticed that a significant majority of crystallizations are done in hanging- rather than sitting-drop configuration, and considering the significant extra labor involved in hanging drops, can only understand this preference as a historical bias. I understand that sometimes one technique works and not the other, but all things being equal, why is hanging drop still "hanging around?" Any insights appreciated... Jacob Keller *** Jacob Pearson Keller Northwestern University Medical Scientist Training Program Dallos Laboratory F. Searle 1-240 2240 Campus Drive Evanston IL 60208 lab: 847.491.2438 cel: 773.608.9185 email: j-kell...@northwestern.edu *** --- Bostjan Kobe ARC Federation Fellow Professor of Structural Biology School of Chemistry and Molecular Biosciences and Institute for Molecular Bioscience Cooper Road University of Queensland Brisbane, Queensland 4072 Australia Phone: +61 7 3365 2132 Fax: +61 7 3365 4699 E-mail: b.k...@uq.edu.au URL: http://profiles.bacs.uq.edu.au/Bostjan.Kobe.html Office: Building 76 Room 452 Notice: If you receive this e-mail by mistake, please notify me, and do not make any use of its contents. I do not waive any privilege, confidentiality or copyright associated with it. Unless stated otherwise, this e-mail represents only the views of the Sender and not the views of The University of Queensland.
Re: [ccp4bb] use of siliconized cover glass
Dear Bernhard and all others who asked for this information: The place we order siliconized cover slides: Atlantic SciTech Group, Inc. 601 E. Linden Ave. Linden, NJ 07036, USA Phone: Tel. 800-720-9483; Fax 877-765-6616 E-mail: sa...@astginc.com www.astginc.com lin - Original Message - From: Bernhard Spingler Date: Thursday, April 30, 2009 2:25 pm Subject: Re: [ccp4bb] use of siliconized cover glass To: Lin Chen > Dear Lin, > > Thanks for your post. Could you please tell me, which other places > sell siliconized cover slides? > > Best regards from Switzerland > > Bernhard > > > ** > Dr. Bernhard Spingler > University of Zurich > Institute of Inorganic Chemistry, Y34F42 > Winterthurerstr. 190 > CH 8057 Zurich > Switzerland > +41 44 635 46 56 > > > At 18:27 30.04.2009, you wrote: > >Drops tend to spread and flatten on non-siliconized cover glass, > >which is why people use siliconized cover slides despite the > >cost. We recently find some places sell siliconized cover slides > at > >much lower prices, These are not as fancy as the Hampton ones in > >terms of packaging, but worked very well for us. > > > > > >- Original Message - > >From: Ed Pozharski > >Date: Thursday, April 30, 2009 6:49 am > >Subject: Re: [ccp4bb] use of siliconized cover glass > >To: CCP4BB@JISCMAIL.AC.UK > > > > > Should help if you use detergents and, of course, they are > cheaper.> > > > > On Wed, 2009-04-29 at 15:38 -0400, Sang Hoon Joo wrote: > > > > I sometimes notice people using non-siliconized cover glass > and it > > > > makes me wonder what pros and cons we can think about using > > > > siliconized glass... any suggestions? > > > > > > > > Sang Hoon Joo, PhD > > > > Postdoctoral Associate > > > > Duke University > > > > 239 Nanaline H. Duke > > > > Box 3711, DUMC > > > > Durham, NC 27710 > > > -- > > > Edwin Pozharski, PhD, Assistant Professor > > > University of Maryland, Baltimore > > > -- > > > When the Way is forgotten duty and justice appear; > > > Then knowledge and wisdom are born along with hypocrisy. > > > When harmonious relationships dissolve then respect and devotion > > > arise;When a nation falls to chaos then loyalty and patriotism are > > > born.-- / Lao Tse / > > > > > >
Re: [ccp4bb] Hanging vs. Sitting
There is really not much difference in terms of setup between hanging and sitting drop, especially if the drops are set up on tape. Visualization is also usually easier with hanging drops. Bostjan On 1/05/09 1:37 AM, "Poul Nissen" wrote: > We often find results to be very different between hanging and sitting > drops (equilibration kinetics for one may be the explanation). Then > there's the good thing of hanging drops that crystals rarely stick to > the surface of the support facilitating the mounting procedure, in > particular for fragile crystals. > All in all we much prefer hanging drops for our membrane proteins - > the bottle neck is not in the extra few minutes for set-up, but in the > months it takes to produce the protein. > > Poul > On 30/04/2009, at 16.45, Jacob Keller wrote: > >> I have noticed that a significant majority of crystallizations are >> done in hanging- rather than sitting-drop configuration, and >> considering the significant extra labor involved in hanging drops, >> can only understand this preference as a historical bias. I >> understand that sometimes one technique works and not the other, but >> all things being equal, why is hanging drop still "hanging around?" >> Any insights appreciated... >> >> Jacob Keller >> >> *** >> Jacob Pearson Keller >> Northwestern University >> Medical Scientist Training Program >> Dallos Laboratory >> F. Searle 1-240 >> 2240 Campus Drive >> Evanston IL 60208 >> lab: 847.491.2438 >> cel: 773.608.9185 >> email: j-kell...@northwestern.edu >> *** >> --- Bostjan Kobe ARC Federation Fellow Professor of Structural Biology School of Chemistry and Molecular Biosciences and Institute for Molecular Bioscience Cooper Road University of Queensland Brisbane, Queensland 4072 Australia Phone: +61 7 3365 2132 Fax: +61 7 3365 4699 E-mail: b.k...@uq.edu.au URL: http://profiles.bacs.uq.edu.au/Bostjan.Kobe.html Office: Building 76 Room 452 Notice: If you receive this e-mail by mistake, please notify me, and do not make any use of its contents. I do not waive any privilege, confidentiality or copyright associated with it. Unless stated otherwise, this e-mail represents only the views of the Sender and not the views of The University of Queensland.
[ccp4bb] Postdoctoral position available in Bethesda, Maryland, USA
Postdoctoral Position in Protein Crystallography A postdoctoral position is available immediately at the Department of Biochemistry, Uniformed Services University of the Health Sciences to perform structural and biochemical research on potential drug target proteins from Mycobacterium tuberculosis. Job duties include protein expression and purification, biochemical analysis, and crystal structure determination. Candidates must have a recent Ph.D. degree in biochemistry or a related field, with experience in protein expression and purification and in protein X-ray crystallography. Uniformed Services University is located across the street from the National Institute of Health (NIH) campus in Bethesda, Maryland. The position offers a competitive salary with generous fringe benefits. Interested persons please send CV with names of at least two referees by e-mail to: Shuishu Wang Assistant Professor Department of Biochemistry Uniformed Services University 4301 Jones Bridge Road Bethesda, Maryland 20814 e-mail: shuis...@gmail.com
Re: [ccp4bb] use of siliconized cover glass
Drops tend to spread and flatten on non-siliconized cover glass, which is why people use siliconized cover slides despite the cost. We recently find some places sell siliconized cover slides at much lower prices, These are not as fancy as the Hampton ones in terms of packaging, but worked very well for us. - Original Message - From: Ed Pozharski Date: Thursday, April 30, 2009 6:49 am Subject: Re: [ccp4bb] use of siliconized cover glass To: CCP4BB@JISCMAIL.AC.UK > Should help if you use detergents and, of course, they are cheaper. > > On Wed, 2009-04-29 at 15:38 -0400, Sang Hoon Joo wrote: > > I sometimes notice people using non-siliconized cover glass and it > > makes me wonder what pros and cons we can think about using > > siliconized glass... any suggestions? > > > > Sang Hoon Joo, PhD > > Postdoctoral Associate > > Duke University > > 239 Nanaline H. Duke > > Box 3711, DUMC > > Durham, NC 27710 > -- > Edwin Pozharski, PhD, Assistant Professor > University of Maryland, Baltimore > -- > When the Way is forgotten duty and justice appear; > Then knowledge and wisdom are born along with hypocrisy. > When harmonious relationships dissolve then respect and devotion > arise;When a nation falls to chaos then loyalty and patriotism are > born.-- / Lao Tse / >
Re: [ccp4bb] Hanging vs. Sitting
We often find results to be very different between hanging and sitting drops (equilibration kinetics for one may be the explanation). Then there's the good thing of hanging drops that crystals rarely stick to the surface of the support facilitating the mounting procedure, in particular for fragile crystals. All in all we much prefer hanging drops for our membrane proteins - the bottle neck is not in the extra few minutes for set-up, but in the months it takes to produce the protein. Poul On 30/04/2009, at 16.45, Jacob Keller wrote: I have noticed that a significant majority of crystallizations are done in hanging- rather than sitting-drop configuration, and considering the significant extra labor involved in hanging drops, can only understand this preference as a historical bias. I understand that sometimes one technique works and not the other, but all things being equal, why is hanging drop still "hanging around?" Any insights appreciated... Jacob Keller *** Jacob Pearson Keller Northwestern University Medical Scientist Training Program Dallos Laboratory F. Searle 1-240 2240 Campus Drive Evanston IL 60208 lab: 847.491.2438 cel: 773.608.9185 email: j-kell...@northwestern.edu ***
[ccp4bb] Hanging vs. Sitting
I have noticed that a significant majority of crystallizations are done in hanging- rather than sitting-drop configuration, and considering the significant extra labor involved in hanging drops, can only understand this preference as a historical bias. I understand that sometimes one technique works and not the other, but all things being equal, why is hanging drop still "hanging around?" Any insights appreciated... Jacob Keller *** Jacob Pearson Keller Northwestern University Medical Scientist Training Program Dallos Laboratory F. Searle 1-240 2240 Campus Drive Evanston IL 60208 lab: 847.491.2438 cel: 773.608.9185 email: j-kell...@northwestern.edu ***
Re: [ccp4bb] use of siliconized cover glass
Should help if you use detergents and, of course, they are cheaper. On Wed, 2009-04-29 at 15:38 -0400, Sang Hoon Joo wrote: > I sometimes notice people using non-siliconized cover glass and it > makes me wonder what pros and cons we can think about using > siliconized glass... any suggestions? > > Sang Hoon Joo, PhD > Postdoctoral Associate > Duke University > 239 Nanaline H. Duke > Box 3711, DUMC > Durham, NC 27710 -- Edwin Pozharski, PhD, Assistant Professor University of Maryland, Baltimore -- When the Way is forgotten duty and justice appear; Then knowledge and wisdom are born along with hypocrisy. When harmonious relationships dissolve then respect and devotion arise; When a nation falls to chaos then loyalty and patriotism are born. -- / Lao Tse /
