Eppendorf G0.5 µPlate - Manual (Page 27)

Calculations
Eppendorf ® μPlate G0.5
English (EN)
27
9.2 Blank values
9.2.1 Determining the average blank value
The average absorbance value at 340 nm, which was determined for all wells used for
blanking, is subtracted from the average absorbance value at 260 nm or 280 nm. The
relative deviation of the wells used to determine the average blank value must be under 10
% to ensure that a measurement can be started.
Ext
average blank value
= Ext
260 average
– Ext
340 average
[OD]
9.2.2 Determining the individual blank values
The well-specific absorbance value at 340 nm is subtracted from the corresponding
absorbance value at 260 nm.
Ext
blank value A1
= Ext
260 A1
– Ext
340 A1
[OD]
Ext
blank value A2
= Ext
260 A2
– Ext
340 A2
[OD]
Ext
blank value B1
= Ext
260 B1
– Ext
340 B1
[OD]
etc.
For each well used, the corresponding blank value is saved. The blank value correction for
each sample is carried out using the corresponding individual blank value (of the affected
well) instead of an average blank value. Each well that is used for the sample
measurement must have been previously taken into account for blank value
determination.
9.3 Samples
9.3.1 Calculations based on an average blank value
The well-specific absorbance value at 340 nm is subtracted from the corresponding
absorbance value at 260 nm. Then, a value is determined using the average value for each
well used for the sample measurement.
Ext
A1
= (Ext
260 A1
– Ext
340 A1
) – Ext
average blank value
[OD]
Ext
A2
= (Ext
260 A2
– Ext
340 A2
) – Ext
average blank value
[OD]
Ext
B1
= (Ext
260 B1
– Ext
340 B1
) – Ext
average blank value
[OD]
etc.