Eppendorf D30 BioPhotometer - Manual (Page 74)

Evaluation procedure
Eppendorf BioPhotometer
® D30
English (EN)
74
12.1.3 Cuvette correction
All absorbance values which are used for result calculation are standardized to the cuvette layer thickness
of 10 mm. If a cuvette with a different path length is used, this path length must be defined in the
cuvette
parameter. In this case, the measured absorbances are corrected to match measuring results with a cuvette
layer thickness of 10 mm before converting them to sample results.
This correction is applied to:
• Methods with evaluation by factor.
• Methods of the Absorbance group, for which only absorbance values are output
The correction is not applied to:
• Methods with evaluation by standards, as we presume that standards and samples are measured in
cuvettes of the same layer thickness.
• Calculation of ratios as A
260
/A
280
(for nucleic acid measurements).
A
XXX, corrCuv
= calculated corrected absorbance at a wavelength of XXX nm.
A
XXX
= measured absorbance at a wavelength of XXX nm.
Cuv = path length of the cuvette.
12.2 Evaluation with factor or standard
C = calculated concentration.
A = absorbance.
F = factor.
The factor is programmed in the parameter list and can be modified. It always relates to an optical path
length of the cuvette of 10 mm. If you change the
Cuvette parameter the device will take the modification
into account when calculating the results. Therefore you do not need to change the factor for the
evaluation.
If, on the other hand, you modify the concentration unit, you have to ensure that the factor is adjusted for
the selected unit.
Cuv
A A
XXX corrCuv XXX
10
,
u
F A C
u