Quantification of nucleic acids

Nucleic acids are typically quantitated based on their absorbance of ultraviolet light. Each base has a different absorbance maximum, with the average being at 260 nm. Ambion has a good site that gives a variety of parameters for nucleotides and nucleic acids [1].

Quantification of RNA

• RNA blotting or Northern blotting
• ribonuclease protection assays (RPA)
• Q-PCR or more specifically QRT-PCR

RNA blotting and RPAs are the gold standards, since no amplification is involved, but require more RNA. Q-PCR is the most sensitive method and can discriminate closely related mRNAs. It is therefore suitable for quickly quantifying low amounts of RNA.

Quantification of DNA

• DNA blotting or Southern blotting
• Q-PCR