Streptavidin—Amplification and Isolation
For improved detection sensitivity, steptavidin-based amplification techniques are widely used in flow cytometry, fluorescent imaging, western blotting or microplate-based detection. Fluorescent conjugates of streptavidin are used to detect biotinylated biomolecules such as primary and secondary antibodies, ligands and toxins or DNA probes for in situ hybridization. Streptavidin-conjugated magnetic beads can be used to isolate proteins, cells, DNA as well as be used in immunoassays or biopanning.
The family of biotin-binding proteins includes streptavidin, avidin, and NeutrAvidin® protein. Each protein binds four biotins per molecule with high affinity and selectivity. The most commonly used is streptavidin, which is non-glycosylated and exhibits low levels of nonspecific binding. Avidin is a highly cationic glycoprotein with an isoelectric point of about 10.5. Its positively charged residues and oligosaccharide component can interact nonspecifically, causing background problems in some applications. NeutrAvidin® protein has been processed to remove the carbohydrate and lower its isoelectric point, which can result in reduced background staining.
|Use these tools to select the optimal technique for your target abundance with complementary detection wavelengths that enable you to multiplex your experiment.|