Hi:
I think having multiple angles is actually important as NOT all
proteins are isotropic scatterers, and therefore show angle
dependence. That is especially true for large MW or very extended
proteins.
If you work with small proteins, can buy the Nanostar which gives you
both DLS/static light scattering detection for a smaller cost. Can
operate in batch with a small cuvette or on-line and it is also temp
controlled. But if you have the money, MALS is better I think - it
gives you more flexibility. As someone already said Wyatt has good
customer support...
Alex
Alexandra Deaconescu, Ph.D.
-----------------------------------
Postdoctoral Fellow of the Damon Runyon Cancer Research Foundation
c/o Grigorieff Laboratory
Brandeis University
http://people.brandeis.edu/~deacona
For mail:
Brandeis University
415 South St., MS 029
Rosenstiel Center
Waltham, MA 02454
For packages (FEDEX):
Brandeis University
415 South St., Kalman Receiving Dock
Waltham, MA 02454
On Jun 20, 2010, at 7:00 PM, CCP4BB automatic digest system wrote:
> There are 3 messages totaling 335 lines in this issue.
>
> Topics of the day:
>
> 1. Production Scientist / Senior Lab Technician
> 2. LS / RI detector systems (2)
>
> ----------------------------------------------------------------------
>
> Date: Sun, 20 Jun 2010 06:54:35 +0100
> From: Tony Savill <[log in to unmask]>
> Subject: Production Scientist / Senior Lab Technician
>
> Molecular Dimensions have an immediate vacancy for a senior lab
> technician
> to join our young team of Production Scientists. The work involves
> reagent
> preparation, dispensing and preparation of our crystal growth
> screening
> kits. Applications and CV's should be sent to the address below.
>
>
>
> Tony Savill
>
> Managing Director
>
> Molecular Dimensions Limited
>
> WE HAVE MOVED!
>
> Unit 6 Goodwin Business Park
>
> Willie Snaith Road
>
> Newmarket
>
> Suffolk
>
> CB8 7SQ
>
> Tel: 01638 561051
>
> Fax: 01638 660674
>
>
>
> Registered Address Only
>
> 88 High Street
>
> Newmarket
>
> Suffolk
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>
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>
>
>
> ------------------------------
>
> Date: Sun, 20 Jun 2010 14:27:55 +0300
> From: Tommi Kajander <[log in to unmask]>
> Subject: LS / RI detector systems
>
> Dear All,
>
> I would like to ask people's comments on usage/preferences on
> different
> providers MALLS/RALS detectors and RI detectors (to combine with
> HPLC SEC)
>
> Mainly we are looking at Wyatt vs Viscotek (or perhaps Varian/Agilent
> now also) tetradetektors(or triple) detectors at the moment, i am not
> aware of many other options..
>
> In particular what is your take on Wyatt MALSS accuracy *(why bother
> with several angles???? although i kind of like the software and
> instrument...)
> vs RALS for proteins
> (which end up being angle independent in scattering anyhow) --or what
> do you think overall of the different manufacturers equipments
> accuracy, etc...
> e.g. viscometer seems rather unnessary to me, as does online DLs..
>
> Thanks for comments,
> Tommi
>
>
> --
> Tommi Kajander, Ph.D., Docent
> Macromolecular X-ray Crystallography
> Research Program in Structural Biology and Biophysics
> Institute of Biotechnology
> P.O. Box 65 (Street address: Viikinkaari 1, 4th floor)
> University of Helsinki
> FIN-00014 Helsinki, Finland
> Tel. +358-9-191 58903
> Fax +358-9-191 59940
>
> ------------------------------
>
> Date: Sun, 20 Jun 2010 07:57:27 -0400
> From: Kushol Gupta <[log in to unmask]>
> Subject: Re: LS / RI detector systems
>
> Hi Tommy,
>
> While I cannot comment on the Viscotek or Varian/Agilent products, I
> can say a few things about the Wyatt product:
>
> We have a Dawn Heleos II 18-angle instrument with inline QELS here
> in the lab along with one of their older Optilab RI instruments. We
> use TSK columns for protein characterizations and GE S200-like
> columns for protein-nucleic acid complexes. We've had the set-up
> for about 18 months now, and we're very happy with the product.
> It's become a routine-use instrument in the lab for the
> characterization of protein and protein-nucleic acid preparations
> that are about to go into crystal trials and SAXS experiments. If
> used properly, the accuracy and reproducibility of the mass
> determinations for protein samples are very good - usually within a
> few percent of actual mass and about as good as what I would get
> from an AUC sedimentation equilibrium experiment. (This becomes a
> trickier issue with composite particles like protein-DNA, as you
> have to implement a mass-averaged dn/dc figure and so on) We've
> used it successfully on systems where the particles range from 12 kD
> to upwards of 660 kD. The customer technical support is good, too.
>
> Hope this helps,
>
> Kushol
>
> Kushol Gupta, Ph.D.
> Research Associate
> Van Duyne Laboratory - HHMI/Univ. of Pennsylvania School of Medicine
> [log in to unmask]
> 215-573-7260 / 267-259-0082
> -----Original Message-----
> From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf
> Of Tommi Kajander
> Sent: Sunday, June 20, 2010 7:28 AM
> To: [log in to unmask]
> Subject: [ccp4bb] LS / RI detector systems
>
> Dear All,
>
> I would like to ask people's comments on usage/preferences on
> different
> providers MALLS/RALS detectors and RI detectors (to combine with
> HPLC SEC)
>
> Mainly we are looking at Wyatt vs Viscotek (or perhaps Varian/Agilent
> now also) tetradetektors(or triple) detectors at the moment, i am not
> aware of many other options..
>
> In particular what is your take on Wyatt MALSS accuracy *(why bother
> with several angles???? although i kind of like the software and
> instrument...)
> vs RALS for proteins
> (which end up being angle independent in scattering anyhow) --or what
> do you think overall of the different manufacturers equipments
> accuracy, etc...
> e.g. viscometer seems rather unnessary to me, as does online DLs..
>
> Thanks for comments,
> Tommi
>
>
> --
> Tommi Kajander, Ph.D., Docent
> Macromolecular X-ray Crystallography
> Research Program in Structural Biology and Biophysics
> Institute of Biotechnology
> P.O. Box 65 (Street address: Viikinkaari 1, 4th floor)
> University of Helsinki
> FIN-00014 Helsinki, Finland
> Tel. +358-9-191 58903
> Fax +358-9-191 59940
>
> ------------------------------
>
> End of CCP4BB Digest - 19 Jun 2010 to 20 Jun 2010 (#2010-166)
> *************************************************************
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