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Learning Center
Micro-Volume Sampling—How it Works
Thermo Scientific
NanoDrop One
C
with NanoDropQC Software User Guide
47
Absorbance Spectrum
The light passes through the liquid column to the
detector, which generates a spectrum of absorbance
versus wavelength. The spectrum shows the amount of
light absorbed by the molecules of the sample at each
measured wavelength.
Note
: To prevent evaporation, which affects
measurement accuracy, close the arm quickly after you
finish loading a sample or blank.
The example at the left shows a typical absorbance
spectrum taken of a nucleic acid sample. The spectrum
is measured from 190 nm to 850 nm. The displayed
range may vary for each application.
Sample Absorbance
When the instrument is blanked, a reference spectrum is
taken of the blanking solution and stored in memory.
For each sample measurement, the sample intensities
along with the blank intensities are used to calculate the
total absorbance of the sample according to the
equation at the left.
Baseline Correction
For some applications, the instrument can be set up to
apply a baseline correction to each measurement to
minimize any offset caused by light scattering
particulates in the sample spectra. The correction
subtracts the absorbance value at a reference wavelength
that is close to zero from the absorbance value at each
wavelength across the spectrum, essentially “anchoring”
the spectrum to zero absorbance units at the reference
wavelength.
Absorbance
intensity
sample
intensity
blank
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