Silica Technology The binding of DNA to silica matrices has been a time saver for many researchers. For example, GLASSMILK® from BIO 101 is a silica matrix that binds nucleic acids rapidly, quantitatively, and specifically. Glass binding and elution properties vary with pH and salt concentration; low pH and high salt promote binding while dissociation of the bound nucleic acid occurs at high pH and low salt concentration. The downside to using silica resins or slurries is that they can carry over and interfere with downstream applications and be a potential source of endotoxin contamination. However, the incorporation of silica on columns minimizes these problems. Nucleic acids are adsorbed to the silica gel membrane in the presence of high concentrations of chaotropic salts, and unwanted cellular debris, polysaccharides, and proteins are spun through. After washing, nucleic acids are eluted in small volumes of low-salt buffer, ready for use. Another silica-based technology used in products such as Bio-Rad's Quantum Prep plasmid purification kits makes use of diatomaceous earth. The unique DNA-binding matrix in these kits is made up of the SiO2-rich exoskeletons of diatoms, the highly porous nature of which increases surface area available for DNA binding.