340nm

340nm refers to a wavelength of light, specifically 340 nanometers. Nanometers are a unit of length equal to one billionth of a meter. Light with a wavelength of 340nm falls within the ultraviolet (UV) portion of the electromagnetic spectrum. Specifically, it is in the UV-B range, though it is very close to the boundary of UV-A. UV-B radiation is known for its biological effects, including its role in vitamin D production in the skin and its potential to cause sunburn and DNA damage. In scientific applications, 340nm is a common wavelength used in spectrophotometry for quantitative analysis of various substances. Many biochemical assays utilize reagents that absorb light at this specific wavelength, allowing for the measurement of enzyme activity or the concentration of certain molecules. For example, the reduction of NAD(P)H, which has a strong absorbance at 340nm, is a common indicator in many enzymatic reactions. Spectrophotometers are calibrated and operated using light sources that can produce a stable and measurable output at 340nm. The intensity of light at this wavelength can also be used to determine the concentration of solutions based on Beer-Lambert Law.