Streptavidin Rhodamine Conjugated

Streptavidin is isolated from bacteria, Streptomyces avidinii, and has an exceptionally high binding affinity for B7 (biotin). Rockland offers streptavidin in unconjugated and conjugated forms for common immunoassays including ELISA, western blotting, immunohistochemistry. Streptavidin is a tetrameric protein capable of binding 4 biotin groups to each molecule of streptavidin. While streptavidin has identical binding properties as avidin, it lacks the glycoprotein portion of the molecule and therefore shows less non-specific binding. Streptavidin is a slightly smaller molecule with a molecular weight of approximately 53.6 kDa. The sequence of avidin only shows 30% homology with streptavidin, and anti-avidin and anti-streptavidin antibodies are not immunologically cross reactive. Rockland Immunochemicals conjugates Rhodamine to Affinity Purified antibodies, avidin, streptavidin and F(ab)2 Fragments of Affinity Purified Antibodies. The molar ratio of Rhodamine to protein (F/P ratio) in the conjugate ranges from 2 - 3. Rhodamine fluorochrome perform extremely well in double label experiments with fluorescein.