膜杰作
Star Staining
分子别名（Synonym）
Streptavidin,SA
表达区间及表达系统（Source）
Streptavidin Protein-Acridinium ester (STN-NA114) is Acridinium ester chemically conjugated Streptavidin expressed from E. coli cells.
蛋白结构（Molecular Characterization）
Streptavidin carries no "tag". The protein has a calculated MW of 13.8 kDa. The protein migrates as 15-16 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE).
标记（Labeling）
Acridinium ester, can react with the primary amino group of protein. Under alkaline conditions, NHS is replaced as the leaving group, and the protein forms a stable amide bond with Acridinium ester.
蛋白标记度（Protein Ratio）
Passed as determined by binding MPCLIA.
纯度（Purity）
>95% as determined by SDS-PAGE.
>90% as determined by SEC-MALS.
制剂（Formulation）
Lyophilized from 0.22 μm filtered solution in PBS, pH6.3 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.
电泳（SDS-PAGE）
Streptavidin Protein-Acridinium ester on SDS-PAGE under reducing (R) condition. The gel was stained with Coomassie Blue. The purity of the protein is greater than 95% (With Star Ribbon Pre-stained Protein Marker).
SEC-MALS
The purity of Streptavidin Protein-Acridinium ester (Cat. No. STN-NA114) is more than 90% and the molecular weight of this protein is around 55-75 kDa verified by SEC-MALS.
Report
活性（Bioactivity）-MPCLIA
Immobilized 0.04 μg/Test of Biotinylated Human PD-1 Protein, Avitag,His Tag (Cat. No. PD1-H82E4) to the Streptavidin Protein-Acridinium ester (Cat. No. STN-NA114, 0.008 μg/Test), incubated with 20 μL/Test of Human PD-L1 Protein, Mouse IgG1 Fc Tag (Cat. No. PD1-H52A3) at increasing concentration coupled to Anti-Mouse IgG Magnetic Beads (10 μg beads/Test). Detection was performed with sensitivity of 7.8 ng/mL in Magnetism particulate chemiluminescence immunoassay (MPCLIA) (KEYSMILE, SMART 6500S) (QC tested).
Protocol
Immobilized 0.04 μg/Test of Biotinylated SARS-CoV-2 Spike RBD, His,Avitag (Cat. No. SPD-C82E9) to the Streptavidin Protein-Acridinium ester (Cat. No. STN-NA114, 0.008 μg/Test), incubated with 20 μL/Test of Anti-SARS-CoV-2 Spike RBD Antibody, Chimeric mAb, Human IgG1 (AM122) (Cat. No. S1N-M12A1) at increasing concentration coupled to Protein G Magnetic Beads (10 μg beads/Test). Detection was performed with sensitivity of 0.244 ng/mL in Magnetism particulate chemiluminescence immunoassay (MPCLIA) (KEYSMILE, SMART 6500S) (Routinely tested).
Protocol
Immobilized 0.04 μg/Test of Biotinylated SARS-CoV-2 Spike RBD, His,Avitag (Cat. No. SPD-C82E9) to the Streptavidin Protein-Acridinium ester (Cat. No. STN-NA114, 0.008 μg/Test), incubated with 20 μL/Test of Anti-SARS-CoV-2 Spike RBD Antibody, Chimeric mAb, Human IgG1 (AM122) (Cat. No. S1N-M12A1) at increasing concentration coupled to Anti-Human IgG Magnetic Beads (10 μg beads/Test). Detection was performed with sensitivity of 7.8 ng/mL in Magnetism particulate chemiluminescence immunoassay (MPCLIA) (KEYSMILE, SMART 6500S) (Routinely tested).
Protocol
背景（Background）
Streptavidin is a tetrameric protein purified from the bacterium Streptomyces avidinii, and exhibits high binding affinity for biotin. Able to bind one molecule of biotin with each subunit. Streptavidin (PI=6.0-7.5) has lower level of non-specific binding to various biological components at physiological pH than avidin (PI=7.4), resulting from its isoelectric point (PI).Streptavidin is useful in affinity chromatography, ELISA, immunohistochemistry and Western Blotting.
