Bio-Tek ELx405, Руководство оператора

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| Chapter 5: Performance Verification/Qualification Tests
Liquid Tests
HT models with the accessory 96-tube manifold: Ensure that the
washer is configured for operation with the correct manifold ( 96 or 192 )
(refer to
Manifold Selection
in
Chapter 3 , Operation
). Failure to set the
correct manifold type in the software before operating the washer may
damage the manifold and void your warranty .
Evacuation Efficiency Test
The Evacuation Efficiency test measures the
residual volume
(mean residual
weight) per well after the aspiration aspect of plate washing. The lower the
residual per well, the better the evacuation efficiency of the washer.
A known solution is dispensed into all wells of a previously weighed microplate.
The aspiration program is run and the plate is reweighed in order to calculate the
total residual fluid based on the weight difference. The total residual fluid weight
is divided by 96 or 384 as appropriate to obtain the
mean residual weight .
If further testing is necessary (to identify “problem” wells), the supplemental test
is performed. A concentrated dye solution is dispensed to/evacuated from the
wells, and the plate is weighed. Buffer is then pipetted to all wells to bring the
volume of fluid to a consistent measurement level. The optical density of each well
is measured at 630 nm and the background at 450 nm is subtracted to account for
scratches on the plate or particulates in a well. Each well’s residual volume is
calculated using its optical density and a calibration factor derived from the mean
residual weight and the mean optical density of all wells on the plate. It is
assumed that 1 mg = 1 µl of fluid for this calculation.
Dispense Precision Test
The Dispense Precision Test measures the variability of the volumes
dispensed from tube to tube across the manifold. In this test, a blue dye solution
is dispensed into a microplate. The optical density of each well is measured at 630
nm and the background at 450 nm is subtracted to account for scratches on the
plate or particulates in the well. The average error percentage is calculated and the
amount dispensed to each well is calculated.
Acceptance is based on the %CV (%Coefficient of Variation), or the ratio of the
standard deviation of the distribution of fluid volumes in the wells to the mean
value of volume per well. The lower the %CV, the better the uniformity across the
manifold.
Bio-Tek Instruments, Inc.