[RASMB] Centerpiece question

[John Sumida]

Dear RASMB

 

Thank you for your responses to my question.  For the Stafford meniscus
matching centerpieces what is the max volume that you can fill these
centerpieces to?

 

Best regards,

John Sumida

University of Washington

 

From: RASMB [mailto:rasmb-bounces at list.rasmb.org] On Behalf Of Karl Maluf
Sent: Thursday, December 18, 2014 11:03 AM
To: rasmb at rasmb.org
Subject: Re: [RASMB] Centerpiece question

 

The other issue with the meniscus matching centerpeices is to be careful to
not overfill the buffer channel higher than the top capillary.  This
prevents equalization of the pressures between the two channels, and can
inhibit the desired meniscus matching.

 

Karl

 

  _____  

From: RASMB [mailto:rasmb-bounces at list.rasmb.org] On Behalf Of John Philo
Sent: Thursday, December 18, 2014 10:49 AM
To: 'John Sumida'; rasmb at rasmb.org
Subject: Re: [RASMB] Centerpiece question

John, in my view the advantages of the Stafford meniscus-matching design
(available from Spin Analytical) over the synthetic boundary centerpieces
are that the long capillary design inhibits diffusion between the two
channels and any inadvertent fluid transfer during loading and handling. The
drawback of that long channel though is that it is harder to get the
transfer needed to match the heights (it takes more force)---I find I may
need to go to 10-12 K rpm. For some of the virus samples we run that is >=
to the run speed, so you have to do it very quickly to avoid significant
sedimentation during the meniscus matching spin.

 

John

 

From: RASMB [mailto:rasmb-bounces at list.rasmb.org] On Behalf Of John Sumida
Sent: Thursday, December 18, 2014 9:45 AM
To: rasmb at rasmb.org
Subject: [RASMB] Centerpiece question

 

Dear RASMB,

 

For interference measurements where matching the sample and reference
channel menisci is essential, is there a preference for either the meniscus
matching centerpiece versus synthetic boundary centerpiece.  We would be
interested to hear about pros and cons.

 

Thank you and happy holidays.

 

Best regards,

 

John Sumida, Ph.D.

 <http://depts.washington.edu/cidb4bio/index.shtml> Analytical Biopharmacy
Core Facility

University of Washington

 <http://www.moles.washington.edu/> Molecular Engineering & Sciences
Institute, G22

3946 West Stevens Way NE

Seattle WA 98195-1653

 

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