Dear all,
We have good experience with the ITC200 and we do not consider as a
real limitation the consequence of the small volume. In fact, this is
not only the absolute amount of heat to be measured that is important
because such microcalorimeters measure a power in µcal/s. This is
where another factor, the time response of the instrument, is
important because a longer time response (10 s for the VP-ITC and 3.5
s for the ITC200) 'dilutes' the signal and lowers the measured power.
See simulations on our web site:
http://www-ibmc.u-strasbg.fr:8080/webMathematica/kinITCdemo/index.jsp
In addition, a smaller time response going with a smaller cell volume
is very favourable for using our newly developed kinITC technique.
Again, see our web site and also JACS 134(2012)559.
Last, but not least, you need much less material and much less time
for doing experiments with an ITC200 in comparison of what is needed
with a VP-ITC.!!!
We have no experience with TA instruments.
Philippe DUMAS, responsable d'équipe
Directeur de Recherche au CNRS
Equipe de Biophysique & Biologie Structurale
Unité 'Architecture & Réactivité de l'ARN', UPR9002
Institut de Biologie Moléculaire et Cellulaire
15, rue René Descartes F67084 STRASBOURG
+33 (0)388 41 70 02
http://www-ibmc.u-strasbg.fr/arn/Dumas/index_dum_fr.html
Scott Thomas Walsh <[email protected]> a écrit :
Dear Jose,
I have an iTC200 in my lab and have experience with a VP-ITC. The
major problem with
the iTC200 is that GE has not increased the sensitivity of the
instrument. Thus, you must use
higher concentrations in both the cell and syringe to see measurable
heats. The syringe on the
iTC200 holds 40 uLs. The other issue is the quality of the products
from GE. I have replaced
2 boards on the instrument and replaced the washing module. GE
manufacturing is going down
hill and there equipment is really expensive.
I would really consider demoing TA instruments. I have done this
for purchase of a capillary DSC
instruments. TA instruments quoted me $75,000 for their cap DSC.
The similar cap DSC by GE was
quoted for $150,000. We are purchasing the cap DSC from TA
instruments. In retrospect, I should have
done the same thing for the ITC instruments.
Cheers,
Scott
************************************************
Scott T. R. Walsh, Ph.D.
Assistant Professor
University of Maryland College Park
Dept of Cell Biology and Molecular Genetics
Institute for Bioscience and Biotechnology Research
Rm 3127E SG II
9600 Gudelsky Drive
Rockville, MD 20850
email: [email protected]
phone: (240) 314-6478
fax: (240) 314-6255
On Jan 17, 2012, at 11:02 AM, Jose Artur Brito wrote:
Dear All,
sorry for this off-topic questions but I would like to have some
feed-back from you on Isothermal Titration Calorimetry (ITC) equipments.
We have a very nice quotation for an iTC200 from GE Healthcare. We
wanted this one because it uses ~200uL sample per measurement (really
nice when your dealing with "precious" samples, ie., proteins with low
expression yields). However, I was told that, although consuming much
less sample, is not as good (sensitivity, mixing issues, bubbles, ...),
as the VP-ITC (it uses ~1.4mL per measurement, seven times more than the
iTC200).
Does anyone has experience with these two equipments? Would you prefer
one over the other (please state your reasons)? Would you suggest
another equipment/brand for the ITC (like the NanoITC from TA Instruments)?
Thanks in advance,
Jose Artur Brito
--
************************************************
* José Artur Brito, PhD *
* *
* Post-Doctoral Fellow *
* Membrane Protein Crystallography Lab *
* Instituto de Tecnologia Química e Biológica *
* Oeiras - Portugal *
* *
* Tel.: +351.21.446.97.61 *
* Fax: +351.21.443.36.44 *
* *
* E-mail: [email protected] *
* URL: http://mx.itqb.unl.pt *
************************************************
