New Magnetic Beads Conjugated With Silica 300NM For DNA/RNA Extraction 5ML Unable to locate an expiration date. Both bottles are sealed. Listing is for a total of 2 bottles as shown in the first picture. Multiple pictures are shown so you can read the label. Photos are of the actual item. The GeneNano silica magnetic particles are produced by hydrolysis of orthosilicates in the presence of magnetite have a hydrophilic surface with terminal Si-OH bonds and can easily be separated with conventional permanent magnets. They are extremely stable in organic solvents and at high temperatures. The silica magnetic beads can be used for nucleic acid isolation and purification through the DNA/RNA-silica interaction method created by Boom et al. in 1990, with improved efficiency and simplified operation. The silica magnetic beads are also available with functional protein ligands (avidin, streptavidin, protein A, albumin) or biotin. They can be offered with the nickel (II) chelator nitrilotriacetic acid (NTA) or ready to use with the corresponding nickel complex (Ni-NTA) for the binding of histidine-labeled proteins.