Streptavidin (Beta Galactosidase), Highly Purified

Streptavidin is a biotin-binding protein found in the culture broth of the bacterium Streptomyces avidinii. Like its namesake avidin, streptavidin binds 4 moles of biotin per mole of protein with a high affinity virtually unmatched in nature (Kd~10-15). Streptavidin lacks carbohydrate side chains present on avidin and has an isoelectric point nearer to neutrality where most useful biological interactions occur (pI of 5-6 vs 10 for avidin). As a result, streptavidin frequently exhibits lower levels of non-specific binding than does avidin when the proteins are used in applications relying upon the formation of avidin/biotin complexes (Chaiet and Wolf, 1964). Applications: Suitable for use in ELISA, Western Blot, and Immunohistochemistry. Other applications not tested. Recommended Dilutions: ELISA: 1:100-1:3000 Assayed against 1ug of biotinylated IgG in a standard capture ELISA using OPNG as a substrate for 30 minutes at RT., Optimal dilutions to be determined by researcher. Storage and Stability: Store at 4° C before opening. DO NOT FREEZE. This product is stable at 4°C as an undiluted liquid. Stable for 6 months. Dilute only prior to immediate use. Freezing Beta Galactosidase conjugates will result in a substantial loss of enzymatic activity.