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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'>Dear David,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'>Your post piqued my curiosity. Please forgive my ignorance on the topic, but why is protein viscosity something one would be interested in? And for those who make these types of measurements, what is the variability in protein viscosity?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'>Thank you all for your comments and responses, now and in the past. This bulletin board has been a great learning tool.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'>Best regards,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'>John Sumida<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'>University of Washington<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Courier New";color:blue'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><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"'> RASMB [mailto:rasmb-bounces@list.rasmb.org] <b>On Behalf Of </b>David Hayes<br><b>Sent:</b> Wednesday, June 03, 2015 5:23 AM<br><b>To:</b> RASMB<br><b>Subject:</b> [RASMB] Viscometer technology<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>Hi all (especially hoping Steve Harding is active),<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>I recently saw the Malvern viscosizer. It is a capillary viscometer and taylor dispersion instrument. (Taylor dispersion looks at the diffusion pattern of a small plug of sample in a capillary). Because of the small volumes used, it could be useful for screening early limited supply proteins for viscosity problems.<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>Are there any general thoughts on the technology?<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3436"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'> <o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3437"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>I remember Steve Harding telling us at BITC that you never use rolling ball viscometers on proteins: the proteins stick to the ball.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3438"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>Recently we found out here that the regular Anton Paar cone and plate rheometers sometimes need PS-80 in protein samples or the air water interface around the outside edge can predominate the viscosity measurements.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3439"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'> <o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3440"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>I did ask whether most samples just stick to the capillary and disappear or run anomalously, but the answer was they had a super coating so most things won’t stick. This coating makes the capillary impossible to clean (so you buy more capillaries from Malvern). And that the taylor dispersion fitting will tell you if and approximately how much the sample interacts with the capillary walls.<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3441"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'> <o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3442"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>Kind Regards,<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3443"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'> <o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3457"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>David Hayes<o:p></o:p></span></p></div><div id="yui_3_16_0_1_1433333972801_3394"><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div></div></div></body></html>