Appendices; Instrument Specifications; Blanking And Absorbance Calculations - Thermo Scientific NanoDrop 1000 V3.7 User Manual

19. Appendices

Instrument Specifications

• Sample Size: 1 microliter
• Path Length: 1 mm (with auto-ranging to 0.2 mm)
• Light Source: Xenon flash lamp
• Detector Type: 2048-element linear silicon CCD array
• Wavelength Range: 220-750 nm
• Wavelength Accuracy: 1 nm
• Wavelength Resolution: 3 nm (FWHM at Hg 546 nm)
• Absorbance Precision: 0.003 absorbance ( 1mm path)
• Absorbance Accuracy: 2% (at 0.76 absorbance at 257 nm)
• Absorbance Range: 0.02-75 (10 mm equivalent absorbance)
• Detection Limit: 2 ng/microliter (dsDNA)
• Maximum Concentration: 3700 ng/microliter (dsDNA)
• Measurement Cycle Time: 10 seconds
• Dimensions: 14 cm X 20 cm
• Weight: 1.6 kg
• Sample Pedestal Material of Construction: 303 stainless steel and
quartz fiber
• Operating Voltage: 12 Vdc
• Operating Power Consumption: 6 W
• Standby Power Consumption: 1.5 W
• CE Approval: Units sold in Europe, Australia and New Zealand
• UL/CSA Approval: Units sold in N. America, S. America, Asia and
Africa
• Included in system: software, compatible with Windows 2000 or
XP

Blanking and Absorbance Calculations

When the NanoDrop 1000 Spectrophotometer is "blanked", a
spectrum is taken of a reference material (blank) and stored in
memory as an array of light intensities by wavelength. When a
measurement of a sample is taken, the intensity of light that has
transmitted through the sample is recorded. The sample intensities
along with the blank intensities are used to calculate the sample
absorbance according to the following equation:
Absorbance = -log (Intensity
Thus, the measured light intensity of both the sample and of the blank
are required to calculate the absorbance at a given wavelength.
/Intensity
sample
19-1
Section 19- Appendices
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blank