Section 3-General Operation
3. General Operation
The Sample Retention System
Basic Use
The main steps for using the sample retention system are listed below:
1. With the sampling arm open, pipette the sample onto the lower
measurement pedestal.
2. Close the sampling arm and
initiate a spectral measurement
using the operating software on
the PC. The sample column is
automatically drawn between the
upper and lower measurement
pedestals and the spectral
measurement made.
3. When the measurement is
complete, open the sampling arm
and wipe the sample from both
the upper and lower pedestals
using a soft laboratory wipe.
Simple wiping prevents sample
carryover in successive
measurements for samples
varying by more than 1000 fold in
concentration. See
www.nanodrop.com for
performance data on sample
carryover.
Cleaning the Sample Retention System
Wiping the sample from both the upper and lower pedestals (as shown above) upon completion of each sample
measurement is usually sufficient to prevent sample carryover and avoid residue buildup. Although generally not
necessary, 2 ul water aliquots can be used to clean the measurement surfaces after particularly high concentration
samples to ensure no residual sample is retained on either pedestal. After measuring a large number of samples,
however, it is recommended that the areas around the upper and lower pedestals be cleaned thoroughly. This will prevent
the wiping after each measurement from carrying previous samples onto the measurement pedestals and affecting low-
level measurements. A final cleaning of all surfaces with de-ionized water is also recommended after the user’s last
measurement. Note: Please do not use a squirt bottle to apply de-ionized water.
Decontamination of Measurement Pedestals
If decontamination is necessary, a sanitizing solution, such as a 0.5% solution of sodium hypochlorite (1:10 dilution of
common commercial bleach solutions – freshly prepared), can be used to ensure that no biologically active material is
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