Thermo Scientific NanoDrop One User Manual page 44

4 Nucleic Acid Applications
Measure Microarray
Calculated nucleic acid concentrations are
based on the absorbance value at 260 nm,
the factor used and the sample pathlength.
A single-point baseline correction (or
analysis correction) may also be applied.
Concentration is reported in mass units.
Calculators are available on the Internet to
convert concentration from mass to molar
units based on sample sequence.
Absorbance values at 260 nm, 280 nm and
sometimes 230 nm are used to calculate
purity ratios for the measured nucleic acid
samples. Purity ratios are sensitive to the
presence of contaminants in the sample,
such as residual solvents and reagents
typically used during sample purification.
42 NanoDrop One User Guide
Measured Values
A260 absorbance
Note: The absorbance value at 750 nm is subtracted from all
wavelengths in the spectrum. As a result, the absorbance at
750 nm is zero in the displayed spectra. Also, for
micro-volume absorbance measurements and
measurements taken with nonstandard (other than 10 mm)
cuvettes, the spectra are normalized to a 10 mm pathlength
equivalent.
• Nucleic acid absorbance values for all Microarray
types are measured at 260 nm using the 750-corrected
and normalized spectrum.
• If Analysis Correction
the correction wavelength is subtracted from the
absorbance at 260 nm.
• If one or more dyes are selected, the
values at 260 nm are also subtracted from the
absorbance at 260 nm.
• The final corrected absorbance at 260 nm is reported
and used to calculate sample concentration.
A280 absorbance
• 750-corrected and normalized absorbance value at
280 nm (minus the A280 dye correction) is used to
calculate an A260/A280 ratio.
is selected, the absorbance value at
dye correction
Thermo Scientific
sample