What does OD260 stand for?
The heterocyclic ring structures in DNA and RNA absorb light with a maximum absorbance near 260 nanometers (nm). An OD(260), or optical density 260, is defined as the amount of light at a 260 nm wavelength which will be absorbed by an oligo if it is resuspended in 1 mL water and the concentration is read in a 1 cm quartz cuvette. This method of measurement is considered the most accurate means of assessing the amount of oligonucleotide present following synthesis. The relationship between measured OD260, molar extinction coefficient (ε260), and oligonucleotide concentration is given as: OD260 = ε260 x concentration.