31Which metrics should be considered when evaluating a high-performance spectrometer?32Why are nucleic acids commonly quantified at 260 nm?33Can dsDNA, RNA and ssDNA use the same conversion factor?34Why are sequence-specific extinction coefficients preferable for oligonucleotides?35What does A260/A280 represent?36What are common A260/A280 reference values for DNA and RNA?37Does a normal A260/A280 mean a sample is definitely pure?38Can pH affect A260/A280?39What is A260/A230 used for?40Why are purity ratios often unstable at low concentration?

Why are nucleic acids commonly quantified at 260 nm?

Nucleic acid bases absorb strongly around 260 nm in the UV region. Concentration can be estimated with the conversion factor appropriate to the sample type or a sequence-specific extinction coefficient.