Thermo Scientific NanoDrop Lite Frequently Asked Questions Manual

T129–TECHNICAL BULLETIN NanoDrop Lite

Frequently Asked Questions

Q: What are the sample size requirements for the NanoDrop Lite?
A: Although 1 ul volumes are usually sufficient for most sample measurements, increasing the sample size to 2 ul will

ensure proper column formation for samples with reduced surface tension properties.

Q: Will the sample size affect the concentration results?
A: No. All calculations are volume independent. Sample concentrations for all applications are calculated using the Beer-

Lambert equation, which relates concentration to absorbance using analyte and wavelength specific extin ction
coefficients or conversion factors.

Q: What pathlengths are used to make measurements and is the user required to make any calculations relevant to the

pathlength?

A: The NanoDrop Lite uses a 0.5 mm pathlength and all reported concentration results have taken into account the

pathlength. The absorbance reported for all measurements is normalized to a 10 mm pathlength.

Q: What types of samples can be measured with the NanoDrop Lite?
A: The NanoDrop Lite is designed to measure the absorbance and calculate the concentration of nucleic a cid s (260 nm)

and purified proteins(280 nm). This would include dsDNA, ssDNA, RNA and purified proteins.

Q: Do nucleic acids require purification prior to measurement?
A: Yes. Absorbance measurements are not specific for a particular sample type. Any analyte that absorbs a t 260 nm

(DNA, RNA or free nucleotides) will contribute to the total absorbance of the sample.

Q: What sort of reproducibility and dynamic range should I expect when measuring nucleic acids with the NanoDrop Lite?
A: The dynamic range depends on the nucleic acid being measu re d. Refer to the NanoDrop Lite User Guide for more

information on dynamic range and expected reproducibility.

Q: Do p
A: Yes, making absorbance measurements will be affected by the presence of non-protein molecules which absorb at

Q: What is the dynamic (concentration) range and reproducibility for proteins on the NanoDrop Lite?
A: The dynamic range depends on the assay type selected for the protein b eing measured. Choices are 1A/cm = 1

Q: Can I use colorimetric methods such as Bradford or Pierce 660 with the NanoDrop Lite to determine the total protein

roteins require purification prior to measurement on the NanoDrop Lite?

280 nm. The NanoDrop Lite is not designed to measure non-purified proteins and it does not measure the A280/A260
purity ratio for proteins.

mg/ml, IgG or BSA. Refer to the NanoDrop Lite User Guide for more information on dynamic range and expected
reproducibility.

concentration in samples such as cell lysates?

Thermo Scientific NanoDrop Products Wilmington, Delaware USA Technical support:[e-mail]
302-479-7707 Toll free (US & Canada) 877-724-7690 www.thermoscientific.com/nanodrop

T129–TECHNICAL BULLETIN NanoDrop Lite

Page 2

A: No. The Protein A280 application of the NanoDrop Lite is designed for measuring purified proteins that absorb at

280nm. Calculations are based upon Beer’s Law, using a protein specific extinction coefficient. Colorimetric assays
require standard curve generation and absorb light at wavelengths other than 280 nm. If you are currently using a
colorimetric assay to measure proteins, it is recommended that you use one of the preprogrammed colorimetric
methods available on the NanoDrop 2000/2000c.

Q: Is simply wiping the pedestal surface adequate to prevent sample carryover?
A: Yes. The highly polished quartz stainless steel surfaces of the sample retention system are resistant to sample

adherence. Wiping with dry lint-free lab wipes remove samples very effectively. However, if a sample is left to dry on
the pedestal, more extensive cleaning is required. Refer to the technical document,
the NanoDrop Lite, for additional information.

Q. How d

o I clean the pedestals?

A: An application of water at the end of a measurement session is generally all that is necessary to keep the measure

surfaces clean and conditioned. If additional cleaning is required, refer to the technical document,
Reconditioning for the NanoDrop Lite, for additional information. Do not use detergents or isopropanol as cleaning
agents as their use may result in the pedestals becoming unconditioned.

Q: How do I keep my sam

ple from spreading on the pedestal?

A: There are many reagents and organic solvents that could compromise the pedestal surface properties, causing

samples to flatten out rather than bead up. Use the NanoDrop PR-1 reconditioning compound as a rapid means of
reconditioning the pedestals when the pedestal surface properties have been compromised and samples spread out on
the pedestal. PR-1 kits are available through Thermo Fisher Scientific or your local distributor.

Q: What is an appropriate blanking solution?
A: The blanking solution should always be the solvent or buffer used to dissolve the sample, at the same pH and ionic

strength.

Q: Why do I have negative absorbance values?
A: A blank measurement was made either using a solution with more absorbance than the sample buffer or on a dirty

pedestal. Clean the pedestal and make a new blank measurement with a fresh aliquot of the appropriate buffer.

Q: Where is the spectrum from my measurement?
A: The NanoDrop Lite does not collect spectral data. It measures absorbance at three different wavelengths: a reference

wavelength, 260 nm and 280 nm.

Q. What information is included in the sample output data?
A. The sample output data includes sample number (auto-generated 1 through 500), time/date of measure ment, analyte

being measured, absorbance (A260 or A280), and concentration. In addition, the 260/280 purity ratio is supplied for
nucleic acid measurements.

Thermo Scientific NanoDrop Products Wilmington, Delaware USA Technical support:[e-mail]
302-479-7707 Toll free (US & Canada) 877-724-7690 www.thermoscientific.com/nanodrop

Cleanin

g and Reconditioning for

ng and

Cleani

T129 – Rev 1/2012