Streptavidin Purified
| Prod. No.: | S203 |
| Pkg. Size: | 5.0 mg, 10 mg |
| Storage: | -20°C Detailed storage instructions below. |
Description
Background:
Streptavidin is a biotin binding protein present in the fermentation broth of the bacterium Streptomyces avidinii. Each molecule of streptavidin can bind four molecules of biotin with a high affinity constant (Kd~10
-15). Unlike native avidin, streptavidin is not glycosylated and has a near neutral isoelectric point (pI ~ 5-6) vs a pI of 10 for native avidin.
Host Species
Streptomyces avidinii
Formulation
Streptavidin is lyophilized under slight alkaline conditions from deionized water. The final lyophilized protein contains approximately 10% NaCl. Therefore, the streptavidin concentration should be determined by measuring the absobance at A280 nm and calculated using the extinction coefficient.
Source
Streptomyces avidinii
Reconstitution
Reconstitute in highly pure deionized water to 1-15 mg/ml. If buffering is required, add sufficient stock solution of 10-20X phosphate buffered saline (PBS) to bring the final concentration to 1X PBS. Do not reconstitute directly in PBS.
Purity
>98% by SDS-PAGE and HPLC
Storage and Stability
The lyophilized streptavidin is stable for at least one year when stored desicated at –20°C. It is recommended to only reconstitute the amount required for use. However, any unused reconstituted streptavidin should be aliquoted in working volumes without diluting and stored at –20°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles.
Specific Activity
≥ 14.0 U/mg
Isoelectric Point
pI = 5 - 6
Extinction Coeffecient
3.2 (mg/ml)-1 cm-1. A 1.0 mg/ml solution of pure streptavidin will have an absorbance at A280 nm of 3.2 with a 1 cm light path.
Country of Origin
USA
Related Products
Products are for research use only. Not for use in diagnostic or therapeutic procedures.
