Recombinant Streptavidin 3 ( r-SA3)

Streptavidin (SA) has a strong affinity with biotin. The KD affinity constant can reach 10 to 15 m, and the active SA usually exists as a tetramer. Because SA does not contain glycosyl, it has a lower level of non-specific binding than avidin in detection and application. SA has been widely used in enzyme linked immunosorbent assay, immunohistochemistry, time-resolved immunofluorescence technology (TRFIA), quantitative PCR, single-stranded DNA preparation, biological fraction purification , the preparation of monoclonal antibodies and other biotechnological fields.

However, the very high affinity of AS and biotin is generally difficult to separate the combined AS and biotin by gentle methods. Conditions that can be separated will generally cause SA to lose their activity, and the biotin-labeled antibody and antigen will also lose their activity, so the combination of SA and biotin is generally considered to be irreversible. . Recombinant streptavidin 3 (r-sa3), based on natural streptavidin, is modified at the molecular level to significantly reduce the affinity (KD ≈ 10-8m) with biotin, while maintaining the tetrameric structure, which can achieve the combination reversible and dissociation with biotin, and can be used for gentle separation, purification and recycling of biotinylated egg white, antibodies, nucleic acid and other substances. R-sa3 contains cysteine ​​in the molecule, which can achieve directional coupling under certain conditions.

M ： protein molecular weight marker

Channel 1 ： r-SA3

For research only！

Recombinant Streptavidin 3 ( r-SA3) DataSheet