A recent developed DNA extraction method can directly use whole blood as the samples. It is the use of magnetic beads covered with nucleic acid–binding matrices. Its theory is nucleic acid (DNA and RNA) in the solution is specifically adsorbed to the surface of magnetic beads because the following action: (i) shielded intermolecular electrostatic forces, (ii) dehydration of the DNA/RNA and beads surfaces, and (iii) intermolecular hydrogen bond formation in the DNA/RNA–beads contact layer.
Bionew™ DNA micro purification kit is the excellent kit which uses magnetic beads for DNA extraction,especially for samples with micro DNA, such as 5-10μl whole blood, blood spot, saliva, buccal swabs, etc,because small quantities nucleic acid in the lysate is specifically,efficiently adsorbed to the surfaces of magnetic beads but other precipitate in the lysate isn’t adsorbed. And according to the data, the efficiency of adsobing nucleic acid onto the surface of magnetic beads is higher than 90%.