Determining Concentration: The Role of Spectrophotometers
After extracting DNA, many experiments require a precise concentration of the DNA as input material. There are several techniques available for measuring DNA concentration, including UV absorption, fluorescent dyes, and electrophoresis.
DNA spectrophotometers are widely used for this purpose. This article will explain how these instruments function and the reasons they are commonly utilised.
Applications of DNA Spectrophotometers
Spectrophotometry plays a crucial role in various biochemical studies, including the quantification and quality control of DNA, RNA, and proteins. These experiments often involve very low sample quantities, making non-destructive analysis essential. Microvolume spectrophotometers (also known as nano drop or nano volume spectrophotometers) are particularly advantageous, as they require just 1µL of sample for accurate measurement.
Functionality of DNA Spectrophotometers
Spectrophotometry is a technique within electromagnetic spectroscopy that involves quantifying the transmission or reflection properties of a material across different wavelengths. DNA spectrophotometers employ detectors that assess light intensity over a range of wavelengths.
These spectrophotometers are primarily used to measure ultraviolet, infrared, and visible light, but they can also analyse other regions of the electromagnetic spectrum. The wavelength range (or the spectrum of light that passes through the sample) is a key characteristic of DNA spectrophotometers. Additional important features may include sample transmission percentage, logarithmic absorption range, and occasionally, reflectance measurement, depending on the specific application.
In solution, DNA spectrophotometers gauge how much ultraviolet light is absorbed by the nucleic acid bases. DNA and other nucleic acids absorb light most strongly at a wavelength of 260nm. The level of absorption correlates directly with the DNA concentration in the sample. This concentration is determined by calculating the transmitted light using the Beer-Lambert law. The Beer-Lambert law allows researchers to solve for concentration using the formula A = ecl, where A is absorbance, e is the extinction coefficient of the material being measured (e.g. DNA), c is concentration and l is the pathlength used for the spectrophotometer reading.
For accurate DNA quantification, the DNA should be dissolved in a solvent, and the spectrophotometer should be calibrated with the solvent to eliminate any background interference.
Innovative DNA Spectrophotometers from DeNovix
The DS-11 series by DeNovix represents a significant advancement in spectrophotometry. These compact and user-friendly devices offer full-spectrum UV-Vis analysis with fluorescence capability, making them ideal for rapid quantification of nucleic acids and proteins. For more information on how DeNovix DNA spectrophotometers can enhance your DNA quantification processes, contact our instrument specialists.