ThermoFisher Scientific NanoDrop Eight, User Manual

Page: 87 / 152

7
Learning Center
Prepare Samples and Blanks
Thermo Scientific NanoDrop Eight User Guide 87
Preparing Samples
• Isolate and purify samples before measuring them with the instrument.
Commercial sample isolation kits are available for these purposes, or use an
in-house protocol. After purification, analyte of interest is typically dissolved in
aqueous buffer solution before it is measured.
Tip : Any molecule that absorbs light at analysis wavelength will contribute to
total absorbance value used to calculate sample concentration.
• Ensure final analyte concentration is within instrument’s absorbance detection
limits .
• For micro-volume measurements, gently (but thoroughly) vortex each sample
before taking a measurement.
Avoid introducing bubbles when mixing and pipetting.
Choosing and Measuring a Blank
The buffer used to resuspend a sample analyte can contribute absorbance. Blanking
minimizes any absorbance contribution due to the buffer components from the
sample measurement. The resulting sample spectrum represents the absorbance of
only the analyte of interest.
For best results:
• For most applications, blank with the same
buffer solution used to resuspend the analyte
of interest. The blanking solution should be a
similar pH and ionic strength as the analyte
solution. For details, see “To measure
samples” in the application used.
• Measure new blank before each set of
samples. It is not necessary to blank the
instrument before each sample
measurement unless the samples are
dissolved in different buffer solutions.
• It is recommended to measure a new blank
every 30 minutes.