# Nucleic Acid Quantification DNA can be **quantified** to determine the success of purification techniques. It is most frequently analyzed through *spectrophotometry*: *DNA* absorbs light at a wavelength of *260 nm* *Proteins* absorb light at a wavelength of *280 nm* Generally, an A260 0f 1.0 indicates: - 50 μg/ml of dsDNA - 35 µg/ml of ssDNA An A260/A280 ratio greater than 1.5 is considered a pure sample. Other *organic contaminants* generally absorb light at a wavelength of *230 nm* Other methods of quantifying RNA include: - [[Gel Electrophoresis]] - [[Southern Blot]] ### Sample Normalization ## RNA Quantification > See also: [[Spectrophotometry and Colorimetry]] **RNA quantification** is nearly identical to [[Nucleic Acid Quantification]] and can also be performed using a *spectrophotometer* or *NanoDrop*. *RNA* absorbs light at a wavelength of *260 nm* *Proteins* absorb light at a wavelength of *280 nm* Generally, an A260 0f 1.0 indicates ~40 μg/ml of RNA An *A260/A280* ratio *>1.8* is considered a *pure* sample. - Differs from DNA quantification where >1.5 was pure Other methods of quantifying RNA include: - [[Gel Electrophoresis]] - [[Northern Blot]] - RT-qPCR --- [Comparison of DNA Quantification Methods for Next Generation Sequencing](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4822169/) - Qubit