20 | Chapter 4: Instrument Qualification
Recommendations for Achieving Optimum
Performance
An Installation/Operational/Performance Qualification (IQ/OQ/PQ)
package (PN 7200515) for the Epoch is available upon request.
Contact your local dealer for more information.
• Microplates should be perfectly clean and free from dust or bottom scratches.
Use new microplates from sealed packages. Do not allow dust to settle on the
surface of the solution; use microplate covers when not reading the plate. Filter
solutions to remove particulates that could cause erroneous readings.
• Although the Epoch supports most flat, U-bottom, and V-bottom microplates,
the reader achieves optimum performance with optically clear, flat-bottomed
wells.
• Non-uniformity in the optical density of the well bottoms can cause loss of
accuracy, especially with U- and V-bottom polyvinyl microplates. Check for
this by reading an empty microplate. Dual wavelength readings can eliminate
this problem, or bring the variation in density readings to within acceptable
limits for most measurements.
• Inaccuracy in pipetting has a large effect on measurements, especially if
smaller volumes of liquid are used. For best results, use at least 100 µL per well
in a 96-well plate and 25 µL in a 384-well plate.
• Dispensing solution into 384-well plates often traps air bubbles in the wells.
Dual wavelength reads will cancel most of these errors; however, for best
results, they should be removed by degassing the plate in a vacuum chamber
prior to reading.
• The inclination of the meniscus can cause loss of accuracy in some solutions,
especially with small volumes. Agitate the microplate before reading to help
bring this problem within acceptable limits. Use Tween 20, if possible (or some
other wetting agent), to normalize the meniscus. Some solutions develop
menisci over a period of several minutes. This effect varies with the brand of
microplate and the solution composition. As the center of the meniscus drops
and shortens the light path, the density readings change. The meniscus shape
will stabilize over time.
BioTek
®
Instruments, Inc.
To Next Page
Loading...
Need help?
General
