Sodium azide NaN3 is often used to prevent antibody degradation in 0,02% W/V concentrations. Equitech supplies azide free antibodies on request.The volume (ml) in milliliters of buffered % w/v solutions at the medium pH are also used for DNA extraction Organic (Phenol-Chloroform) Extraction, Non-Organic (Proteinase K and Salting out), Chelex (Ion Exchange Resin) Extraction, EDTA or PBS aqueous.