Streptavidin (Cy5)

Streptavidin is a biotin-binding protein found in the culture broth of the bacterium Streptomyces avidinii. 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).\n\nExcitation Wavelength: 650nm\n\nEmission Wavelength: 667nm \n\nApplications:\nSuitable for Immunofluorescence, ELISA (Fluorescent) and Western Blot.. Other applications not tested.\n\nRecommended Dilutions:\nELISA (Fluorescent): 1:10,000-1:50,000\nImmunofluorescence microscopy: 1:1000-1:5000\nOptimal dilutions to be determined by the researcher.\n\nStorage and Stability: \nMay be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for 6 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer. Cy5 conjugates are sensitive to light.

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SPECIFICATIONS

Catalog Number

S7973-90

Size

500ug

Applications

ELISA, IF, WB

Form

Supplied as a liquid in PBS, pH 7.2, 10mg/ml BSA (IgG and Protease free), 0.01% sodium azide. Labeled with Cy5 (Cyanine 5.29-OSu) (975 daltons). Fluorochrome/Protein Ratio: 6.5 moles Cy5/ mole Streptavidin

Purity

Prepared from chromatographically pure streptavidin. Assay by immunoelectrophoresis resulted in a single precipitin arc against anti-streptavidin.