膜杰作
Star Staining
分子别名（Synonym）
Streptavidin,SA
表达区间及表达系统（Source）
Streptavidin Protein-Cy5 (STN-NC113) is expressed from E. coli cells.
蛋白结构（Molecular Characterization）
This protein carries no "tag".
The protein has a calculated MW of 13.8 kDa.
偶联（Conjugate）
Cy5
Excitation Wavelength: 651 nm
Emission Wavelength: 670 nm
标记（Labeling）
The primary amines in the side chains of lysine residues and the N-terminus of the protein are conjugated with Cy5 using standard chemical labeling method. The residual Cy5 is removed by molecular sieve treatment during purification process.
内毒素（Endotoxin）
Less than 1.0 EU per μg by the LAL method.
纯度（Purity）
>90% as determined by SDS-PAGE.
制剂（Formulation）
Lyophilized from 0.22 μm filtered solution in PBS, pH7.4 with trehalose as protectant.
Contact us for customized product form or formulation.
重构方法（Reconstitution）
Please see Certificate of Analysis for specific instructions.
For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.
存储（Storage）
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please protect from light and avoid repeated freeze-thaw cycles.
This product is stable after storage at:
- -20°C to -70°C for 12 months in lyophilized state;
- -70°C for 3 months under sterile conditions after reconstitution.
活性（Bioactivity）-FACS
5e5 of Anti-CD19 CAR-293 cells were stained with 100 μL of 20 ug/mL Biotinylated Human CD19 (20-291) Protein, Fc, Avitag™, premium grade (Cat. No. CD9-H82F6) and negative control protein respectively, washed and then followed with 2.5 μg/mL of Streptavidin Protein-Cy5 (Cat. No. STN-NC113) and analyzed with FACS. Cy5 signal was used to evaluate the binding activity (QC tested).
Protocol
背景（Background）
Streptavidin is a 66KDa tetrameric protein purified from the bacterium Streptomyces avidinii, and exhibits high binding affinity to biotin. Each unit can bind one biotin. Horseradish peroxidase is metalloenzyme, a 44KDa glycoprotein. When incubate with substrates, it produces a coloured, fluorimetric, or luminescent derivatives, which can be detected and quantified. HRP conjugated Streptavidin is widely used for the detection and quantification of biotinylated proteins.
