Overview; Recommendations For Achieving Optimum Performance - Bio-Tek ELx800 Operator's Manual

42
Chapter 3: Operation
|

Overview

The ELx800 features a 25-pad keypad and a 2-line x 24-character LCD display, allowing
you to access the reader's program menus and print test results. The reader's bidirectional
serial port allows computer control of the instrument, and provides the means for
downloading additional assay definition files to the instrument. This chapter describes the
operation of the
Recommendations for Achieving Optimum
Performance
Microplates should be perfectly clean and free of 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 readers support standard flat, U-bottom, and V-bottom microplates,
optimum performance is achieved 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, which may
result in inaccurate readings. A dual-wavelength reading method usually eliminates these
inaccuracies; however, for best results, remove the air bubbles by degassing the plate in a
vacuum chamber before reading.
The inclination of the meniscus can reduce reading 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.
IMPORTANT!
carrier shipping block has been removed.
open (configurable) assays onboard the ELx800.
Do not turn on the instrument until the
Bio-Tek Instruments, Inc.