膜杰作
Star Staining
分子别名（Synonym）
Streptavidin,SA
表达区间及表达系统（Source）
Streptavidin-PE (STN-NP119) 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）
PE
Excitation Wavelength: 488 nm / 561 nm
Emission Wavelength: 575 nm
应用说明（Application）
Flow Cytometry
We also carry another Premium Grade Streptavidin Protein-PE (STN-NP117), which is produced under more rigorous quality control system that incorporates a comprehensive set of tests including sterility and endotoxin tests, and its performance is carefully validated and tested for compatibility for cell culture use or any other applications in the early preclinical stage.
内毒素（Endotoxin）
Less than 1.0 EU per μg by the LAL method.
制剂（Formulation）
Lyophilized from 0.22 μm filtered solution in PBS, 1.5% BSA, 0.03% ProClin300, 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 24 months in lyophilized state;
- -20°C for 6 months after reconstitution;
- 2-8 °C for 6 months under sterile conditions after reconstitution.
活性（Bioactivity）-FACS
5e5 of Anti-CD19 CAR-293 cells were stained with 100 μL of 20 μg/mL Biotinylated Human CD19 (20-291), Fc,Avitag, premium grade (Cat. No. CD9-H82F6) and negative control protein respectively, washed and then followed with 2.5 μg/mL of Streptavidin-PE (Cat. No. STN-NP119) and analyzed with FACS. PE signal was used to evaluate the binding activity (QC tested).
Protocol
5e5 of Anti-CD19 CAR-293 cells were stained with 100 μL of 20 μg/mL Biotinylated Human CD19 (20-291), 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-PE (ACROBiosystems & Brand 1 & Brand 2) and analyzed with GraphPad Prism 5. The results showed that the activity of PE-SA of ACROBiosystems is higher than other two competing brands (Routinely tested).
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.
