[RASMB] Viscometer

Sophia Kenrick skenrick at wyatt.com
Thu Jun 6 09:13:30 PDT 2013


Dear Richard,

Following up on Will's comment, the Viscostar is definitely the way to go for measuring intrinsic viscosity to give you information about protein structure.  The Viscostar is ideal for the dilute solutions that can be problematic to measure by other methods.

On the other hand, if you are interested in measuring the dynamic viscosity of a concentrated and/or viscous solution, I recommend the dynamic light scattering method published here:  http://onlinelibrary.wiley.com/doi/10.1002/jps.22384/abstract.  Using the Plate Reader, as in the paper, you can make high-throughput measurements of multiple samples, in ultra-low volumes, and as a function of temperature (http://www.wyatt.com/solutions/hardware/dynaproprotein-solutions-plate-reader.html).

Kind regards,
Sophia

-----Original Message-----
From: rasmb-bounces at list.rasmb.org [mailto:rasmb-bounces at list.rasmb.org] On Behalf Of Mattia Rocco
Sent: Thursday, June 06, 2013 6:00 AM
To: rasmb at list.rasmb.org
Subject: Re: [RASMB] Viscometer

I second William's suggestion, I have used the instrument and I find it really good. Of course, it can work also coupled with an UV detector, which in my opinion gives more reliable concentration values since the extinction coefficient can be computed quite accurately from a protein composition (while the dn/dc is more approximate).

Best - Mattia

Il 2013-06-06 14:43 William Wittbold ha scritto:
> Good morning Richard,
> 
>     Wyatt Technology offers the ViscoStar-II 
> (http://www.wyatt.com/solutions/hardware/viscostarii-viscometer.html
> [1]) , a commercially available online differential viscometer. If you 
> have a SEC or GPC system, integrating the ViscoStar-II is 
> straightforward and will provide the specific viscosity of your 
> protein samples. With typical sample volumes for analytical SEC being 
> under 100 ul, this small sample volume requirement is advantageous.
> 
>    Coupling a concentration detector, such as our Optilab T-rEX 
> (http://www.wyatt.com/solutions/hardware/optilab-t-rex-refractive-inde
> x-detector.html
> [2]) will allow for calculations of the intrinsic viscosity as well.
> I'd be happy to discuss our ViscoStar-II or any of our detectors with 
> you. Please let me know if you have any questions.
> 
> Best Regards,
> 
> Will
> 
> William Wittbold | Application Scientist | Northeast Customer Service 
> Manager Wyatt Technology Corporation
> 6300 Hollister Avenue | Santa Barbara, CA 93117-3253
> Phone: (805)681-9009 x 214 | Fax: (805)681-0123
> Web: www.wyatt.com [3] | Skype: willwittbold
> 
> Notice: This e-mail message, together with any attachments, contains 
> information of Wyatt Technology that may be confidential, proprietary, 
> copyrighted, privileged and/or protected work product, and is meant 
> solely for the intended recipient. If you are not the intended 
> recipient, and have received this message in error, please contact the 
> sender immediately, permanently delete the original and any copies of 
> this email and any attachments thereto.
> 
> FROM: rasmb-bounces at list.rasmb.org
> [mailto:rasmb-bounces at list.rasmb.org] ON BEHALF OF Arthur Rowe
> SENT: Thursday, June 06, 2013 6:23 AM
> TO: Richard Kingston
> CC: rasmb at rasmb.org
> SUBJECT: Re: [RASMB] Viscometer
> 
> Hi Richard
> 
> If by 'protein solutions' you solutions of proteins which are 9more or 
> less) 'globular', then you have a serious problem on your hands.
> The 'signal' with which you are dealing (difference in flow or roll 
> time of a ball in a capillary or narrow tube) is very small, and is 
> not readily measurable in solutions of low (<~5 mg/ml) concentration.
> You might want to consider reading through Steve Harding's 1997 review 
> of this area - old, but the basic physical facts have not changed. As 
> regards using commercially available equipment, our own experience in 
> the NCMH is that even with the AMVn rolling ball viscometer, no longer 
> marketed but as good as has ever been made, we struggle to cope with 
> globular proteins. Even with careful pre-treatment of the lining of 
> the tubes to minimise protein-surface interactions.
> 
> A possible way forward is to follow the method published by 
> Szuchet-Derechin and Johnson (1966) and add a small (few %) amount of 
> glycerol to both solution and reference solvent. This increases the 
> level of the 'signal', without - hopefully - any specific 
> glycerol-induced effects.
> 
> However, in the case of your own proposed work, there is a ray of 
> hope. The REPEATABILITY of the (time) measurements for a given tube 
> (or capillary) is normally much better than the REPRODUCIBILITY 
> (experiment to experiment) of e.g. one concentration level to another.
> If it is the temperature dependence of the viscosity you are looking 
> to asses, then by starting at a low temperature and working up (e.g.
> 5º at a time) you just might have enough precision, as you will be 
> working in _relative_ not _absolute_ mode.
> 
> Hope this is helpful.
> 
> Regards to you, and all colleagues
> 
> Arthur
> 
> S.E.Harding (1997) Prog. Biophys. molec. Biol 68 207-262 (pdf
> available)
> 
> S. Szuchet-Derechin & P. Johnson (1966) Euro. Polymer J. 2 115-128
> 
> Professor Arthur J Rowe
> NCMH/Food Sciences
> University of Nottingham
> Sutton Bonington
> Leics LE12 5RD UK
> 
> Tel: +44 115 9516156
> arthur.rowe at nottingham.ac.uk
> 
> On 6 Jun 2013, at 05:14, Richard Kingston wrote:
> 
> Dear all,
> 
> I've become interested in measuring the viscosity of protein solutions 
> at varying temperature, and wondered if anyone on the list could 
> advise on the best way to do this using commercially available 
> instrumentation. While there are many ways to measure viscosity, for 
> protein applications minimizing the required sample volume is pretty 
> critical. I note that Anton Paar sell an instrument that measures both 
> dynamic viscosity and density (SVM 3000 Stabinger viscometer). If you 
> skip the density measurement, the sample requirements look almost 
> "manageable". Cambridge also sell a micro-sample viscometer (Viscolab
> 5000) which uses microlitre volumes.
> 
> I'm having difficulty tracking down people that might have used these 
> or similar instruments, and could comment on the practicalities for 
> protein work. If anyone can offer advice, either on- or off-list, it 
> would be appreciated.
> 
> Many thanks,
> 
> Richard
> 
> Richard Kingston, PhD.
> 
> School of Biological Sciences
> 
> The University of Auckland
> 
> New Zealand
> 
> website: http://persephone.sbs.auckland.ac.nz/richard/lab/ [4]
> 
> _______________________________________________
> RASMB mailing list
> RASMB at list.rasmb.org
> http://list.rasmb.org/listinfo.cgi/rasmb-rasmb.org [5]
> 
> This message and any attachment are intended solely for the addressee 
> and may contain confidential information. If you have received this 
> message in error, please send it back to me, and immediately delete 
> it. Please do not use, copy or disclose the information contained in 
> this message or in any attachment. Any views or opinions expressed by 
> the author of this email do not necessarily reflect the views of the 
> University of Nottingham.
> 
> This message has been checked for viruses but the contents of an 
> attachment may still contain software viruses which could damage your 
> computer system, you are advised to perform your own checks. Email 
> communications with the University of Nottingham may be monitored as 
> permitted by UK legislation.
> 
> 
> 
> Links:
> ------
> [1]
> http://www.wyatt.com/solutions/hardware/viscostarii-viscometer.html
> [2]
> http://www.wyatt.com/solutions/hardware/optilab-t-rex-refractive-index
> -detector.html
> [3] http://www.wyatt.com/
> [4] http://persephone.sbs.auckland.ac.nz/richard/lab/
> [5] http://list.rasmb.org/listinfo.cgi/rasmb-rasmb.org
> 
> _______________________________________________
> RASMB mailing list
> RASMB at list.rasmb.org
> http://list.rasmb.org/listinfo.cgi/rasmb-rasmb.org
_______________________________________________
RASMB mailing list
RASMB at list.rasmb.org
http://list.rasmb.org/listinfo.cgi/rasmb-rasmb.org


More information about the RASMB mailing list