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 <[email protected]>
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
CB8 8JX
Registered in England and Wales Reg No. 1794026
------------------------------
Date: Sun, 20 Jun 2010 14:27:55 +0300
From: Tommi Kajander <[email protected]>
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 <[email protected]>
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
[email protected]
215-573-7260 / 267-259-0082
-----Original Message-----
From: CCP4 bulletin board [mailto:[email protected]] On Behalf
Of Tommi Kajander
Sent: Sunday, June 20, 2010 7:28 AM
To: [email protected]
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)
*************************************************************
