Chemistry
UV-Vis Spectroscopy: Principle and Application
Quick fact
A single molecule of DNA absorbs UV light most strongly at 260 nm, which is how biochemists measure DNA concentration in a sample using a spectrophotometer.
Why this is interesting
Ever wondered how scientists can tell how much of a substance is in a sample just by shining a light on it? UV-Vis spectroscopy does exactly that, and it's used everywhere from water quality testing to forensics.