Eppendorf BioSpectrometer fluorescence - Manual (Page 79)

79
Troubleshooting
Eppendorf BioSpectrometer ® fluorescence
English (EN)
The coefficient of
determination is <0.8. • For methods with evaluation of
standard series via the regression
procedure: The coefficient of
determination for the regression
evaluation indicates a significant
deviation of the measuring points
from the regression line.
• Turbidity of the measuring
solution.
• Measurements at the limits of the
photometric measuring range.
 Accept the result of the standard
evaluation or remeasure the
standards.
 Make sure the measuring solutions
are clear.
The coefficient of
determination for the
regression evaluation of
the standard series is <
0.8. • For methods with evaluation of
standard series via the regression
procedure: If the regression
evaluation for the standard series
was nonlinear, but the standard
evaluation was accepted by the
user, a warning appears after
samples have been measured.
 Use the sample results with the
reservation mentioned or repeat
the measurement of the standard
series and samples.
Scan: Some of the
measured absorbances
are too high and are not
displayed. • For at least one scan wavelength,
the absorbance exceeded the
measuring range.
• Turbidity of the measuring
solution.
• Measurements at the limits of the
photometric measuring range.
 If the non-displayed areas of the
scan are relevant: Dilute the
sample or remove the dilution via
centrifugation and repeat the
measurement.
Absorbance at the
measuring wavelength is
too high.
Emission at the
measuring wavelength is
too high. • Turbidity of the measuring
solution.
• Optical surfaces of the cuvette are
soiled.
• Cuvette has been inserted into the
cuvette shaft facing the wrong
direction.
• Photometry: Too high absorbance
of the measuring solution.
Fluorimetry: Too high emission of
the measuring solution.
 Measure again considering the
possible causes.
The calculated result is
negative. • Measuring solution not prepared
correctly.
• The incorrect factor has been
entered (wrong algebraic sign).
 Measure again considering the
possible causes.
Problem Cause Solution