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General Q What are the system requirements to run CE Expert on my computer?
A For the stand alone version, you need a PC running
Microsoft* Windows* 3.x, Windows 95, or Windows NT*. Also, you must have "Visual
Basic* Run-Time" (vbrun300.dll) installed on your computer (this is included in the
setup package). There is no Macintosh* version at this time (Macintosh users can use CE
Expert Lite from their Web browser).
CE Expert Lite requires a web browser that understands
JavaScript, and it supports the following browser-versions:
- Netscape* 2.02 or higher
- Microsoft Internet Explorer* 3.0 or higher
Q I am using CE Expert Lite. When I click on
the "Calculate" or "Reset" button, nothing happens. What is wrong?
A You probably have JavaScript disabled. In Netscape
4.x, from the Edit menu, choose Preferences. Click on "Advanced," and make sure
that "Enable JavaScript" is checked. If you are using a previous version of
Netscape, from the Options menu, choose Network Preferences, and make sure that
"Enable JavaScript" is checked.
If you are using Internet Explorer, from the Edit menu, choose
Preferences... (Macintosh) or Options... (PC). In the Web Content section, make sure that
"Enable scripting" is checked. If you continue to experience problems, make sure
that "Enable ActiveX*" is not checked.
Q Can I calculate electrokinetic injections
volumes with CE Expert?
A No. The program only calculates hydrodynamic
volumes. To calculate EK injections you need to know the conductivities of the sample and
the buffer and the mobilities of the analytes.
Q (Stand alone version) So why can I input
voltage?
A Voltage is only used to calculate field strength
(volts per cm).
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Q I don't have a Beckman Coulter CE System. Can
I use CE Expert?
A Absolutely. The principles are the same for any CE
system.
Q What is the difference between P/ACE™ 5000,
P/ACE MDQ and Generic CE?
A The length of the outlet stub for the Beckman
Coulter systems is stored in the program; you need only input the length to the detector,
and the program will calculate the total length. For non-standard (generic) CE systems you
must input both the length to the detector and the total length of the capillary. For
P/ACE MDQ and generic CE you are allowed to input pressure values. On the stand alone
version, for P/ACE 2000 and 5000 the only pressure selections are Rinse (20 psi) and
Inject (0.5 psi).
Q I want to do short side injections on a
Beckman Coulter system. Can CE Expert handle this?
A Yes. Select "Generic CE" and input the
short-side length as "length to detector." You will also have to input the total
length manually.
Q I measured the delivery times on my system.
The measured values are close to those calculated by CE Expert but not the same. Why?
A CE Expert uses theoretical equations of
fluid flow to calculate deliveries. It does not correct for pressure ramp times, fluid
compressibilities, or myriad other factors. It assumes that everything you input is
correct. Small variations in capillary diameter, for example, can cause large changes in
fluid delivery. (50 micrometers is not always 50 micrometers -- your capillary supplier
should be able to provide you with the actual diameter of the capillary you are using.)
The software also does not know if your temperature control is accurate and if your
pressure system is properly calibrated. A major factor is the difficulty in getting an
accurate value for viscosity.
Q (Stand alone version) I know that buffer has
twice the viscosity of water. If I input "2" for "viscosity relative to
water" my calculations are still way off. What's wrong?
A Viscosity measurements are complex. Some fluids
exhibit quite different viscosities when at rest or moving slowly than they do when in
faster motion. For example, forcing long-chain polymers through a capillary can cause the
polymers to align which can substantially affect viscosity. The software assumes the
behavior of pure water in calculating fluid delivery. This is suitable for most aqueous
buffers but risky where more complex preparations are considered.
Q Can I include the CE Expert as part of a
validated laboratory method?
A This is not recommended. CE Expert is
intended as a tool for method development and to assist in understanding the practical
aspects of CE. It gives approximate answers based on theory.
Q Can I share CE Expert with others?
A You may freely distribute the software under the
following conditions: CE Expert may not be distributed for profit; the code cannot
be altered in any way; for the stand alone version you must distribute the entire set-up
package intact.
Q How can I learn more about CE Expert?
A
Read the online publication, Capillary Electrophoresis & CE Expert Lite.
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* All trademarks are the property of their respective owners. Where applicable,
the PCR process is covered by patents owned by Roche Molecular Systems, Inc.,
and F. Hoffmann-LaRoche, Ltd.
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