Nanodrop Spectrophotometry
Nanodrop Spectrophotometry - Related Videos
09:28
NanoDrop Microvolume Quantitation of Nucleic Acids
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Cited by 426 •
2010
The use of NanoDrop microvolume systems as practical and efficient alternatives to traditional nucleic acid quantitation methodology is described through the demonstration of two microvolume nucleic acid quantitation protocols.
10:29
Microvolume Protein Concentration Determination using the NanoDrop 2000c Spectrophotometer
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Cited by 129 •
2009
Microvolume samples are quantified by a spectrophotometer system that uses natural surface tension to retain samples without the use of cuvettes or capillaries. The dynamic range of protein concentrations and speed by which they can be measured are greatly increased with this method.
01:16
Spectrophotometry: Introduction
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2024
Spectrophotometry is the quantitative measurement of the absorption, reflection, diffraction, or transmission of electromagnetic radiation through a material as a function of the intensity and wavelength of the radiation. A spectrophotometer is a device used to measure the change in the radiation intensity caused by its interaction with the material. The essential components of a spectrophotometer include a source of electromagnetic radiation, a slot for placing a material to be analyzed, and a...
12:08
Monitoring the Reductive and Oxidative Half-Reactions of a Flavin-Dependent Monooxygenase using Stopped-Flow Spectrophotometry
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Cited by 12 •
2012
We describe the use of a stopped-flow instrument to investigate both the reductive and oxidative half-reactions of Aspergillus fumigatus siderophore A (SidA), a flavin-dependent monooxygenase. We then show the spectra corresponding to the species in the reaction of SidA and we calculate the rate constants for their formation.
12:48
Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays
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Cited by 7 •
2013
We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies.
FAQs
Beer-Lambert law links the amount of light absorbed by a sample with the concentration of the absorbing material. The instrument measures absorbance at a selected wavelength and uses that relationship to estimate how much DNA, RNA, or protein is present. This converts a UV-Vis optical reading into a concentration value for biological sample assessment.
The A260/A280 ratio provides a purity assessment alongside the concentration measurement. For nucleic acid samples, absorbance at 260 nm supplies the principal measurement used for quantification, while comparison with absorbance at 280 nm produces a ratio that helps indicate sample quality. Researchers can therefore judge whether material is suitable for subsequent molecular biology workflows.
Surface tension keeps a small liquid column suspended between the instrument’s optical surfaces, allowing the sample’s absorbance to be measured without requiring a large sample volume. This physical arrangement is central to the microvolume format: it reduces sample consumption while retaining the optical measurement needed to estimate concentration and purity.
Selected wavelengths make the optical measurement relevant to the biological material being assessed. In nucleic acid analysis, 260 nm is commonly used, and the resulting absorbance supports concentration and purity calculations. The same UV-Vis approach can also assess proteins, so wavelength selection helps tailor the readout to the sample type rather than treating every biological sample identically.
A basic workflow requires placing a very small amount of the biological sample so that surface tension forms a liquid column between optical surfaces. The instrument then records absorbance at selected wavelengths and reports concentration and purity-related measurements. Because preparation is minimal, this assessment can be completed rapidly before the sample enters a molecular biology workflow.
It is especially useful when a researcher needs a quick quality check before PCR, sequencing, cloning, or another molecular biology procedure. The method provides concentration and purity information while consuming only a tiny sample volume, making it practical for deciding whether a DNA, RNA, or protein preparation is ready for the next experimental step.