Thermo NanoDrop One User Manual

Measure Protein A205
Thermo Scientific NanoDrop One User Guide 85
Calculations for Protein A205 Measurements
As with the other protein applications, Proteins A205
uses the Beer-Lambert equation to correlate absorbance
with concentration based on the sample’s extinction
coefficient and pathlength.
This application offers three options (shown at right) for
selecting an appropriate extinction coefficient for each
measured sample, to be used in conjunction with Beer’s
Law to calculate sample concentration.
If the extinction coefficient of the sample is known,
choose the
1% (mass) option and enter the value.
Otherwise, calculate the extinction coefficient or choose
the option that best matches the sample solution.
Tip: Ideally, the extinction coefficient should be
determined empirically using a solution of the study
protein at a known concentration using the same buffer.
Available Options for Extinction Coefficient
• 31, assumes
0.1% (1 mg/mL) at 205 nm = 31
• Scopes, assumes
0.1% (1 mg/mL) at 205 nm = 27 + 120 *
(A280/A205)
• Other protein, enter mass extinction coefficient in L/gm-cm for
1mg/mL (0.1%) protein solution
Note: See Sample Type for details.
Calculated protein concentrations are based on the
absorbance value at 205 nm, the selected (or entered)
extinction coefficient and the sample pathlength. A
single-point baseline 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 the sample sequence.
Measured Values
A205 absorbance
Note: 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.
• Protein absorbance values are measured at 205 nm using the
normalized spectrum. If Baseline Correction is not selected, this is the
reported A205 value and the value used to calculate protein
concentration.
•If Baseline Correction is selected, the normalized and
baseline-corrected absorbance value at 205 nm is reported and used to
calculate protein concentration.
A280 absorbance
• Normalized and baseline-corrected (if selected) absorbance value at
280 nm is also reported.

Thermo NanoDrop One Specifications

General

Wavelength Range	190-850 nm
Pathlength	1 mm and 0.2 mm (Auto-ranging)
Detection Limit	2 ng/µL (dsDNA)
Light Source	Xenon flash lamp
Maximum Concentration	15, 000 ng/µL (dsDNA)
Detector	2048-element linear silicon CCD array
Measurement Time	< 5 seconds
Weight	2.0 kg (4.4 lbs)
Nucleic Acid Quantitation	Yes
Protein Quantitation	Yes
Display	7-inch capacitive touch screen
Sample Volume	1-2 μL
Absorbance Precision	±0.002 A
Operating Voltage	100 to 240 V AC
Dimensions (W x D x H)	20 cm x 25 cm x 15 cm (8 in. x 10 in. x 6 in.)
Software	Thermo Scientific™ software
Connectivity	USB, Ethernet, Wi-Fi
Operating Temperature	15 - 35°C
Dimensions	20 cm x 25 cm x 15 cm (8 in. x 10 in. x 6 in.)
Absorbance Range	0 - 550 A (10 mm equivalent)