8.3. Nucleic acid extraction
A denaturing buffer should be used during homogenization to protect the nucleic acids from degradation. The most common denaturants used are: high concentrations of chaotropic (guanidine) salts, strong antioxidants (β-mercaptoethanol), detergents and/or organic solvents. The nucleic acid is purified from the buffer using either cheap, disposable affinity purification columns or even cheaper precipitation with ethanol, isopropanol or lithium chloride (RNA only). Both methods are reliable, though not particularly uniform (Tentcheva et al., 2006). Affinity columns generally produce cleaner nucleic acid samples, due to the column washing steps. Precipitation can produce higher yields, since columns have a limited binding capacity, or extract volume, equivalent to ~¼ bee.