膜杰作
Star Staining
分子别名（Synonym）
S1 protein NTD,Spike protein S1 NTD,BetaCoV S1-NTD
表达区间及表达系统（Source）
FITC-Labeled SARS-CoV-2 Spike NTD, His Tag (SPD-CF2H3) is expressed from human 293 cells (HEK293). It contains AA Ser 13 - Leu 303 (Accession # QHD43416.1).
Predicted N-terminus: Ser 13
Request for sequence
蛋白结构（Molecular Characterization）
This protein carries a polyhistidine tag at the C-terminus
The protein has a calculated MW of 34.9 kDa. The protein migrates as 53-63 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.
偶联（Conjugate）
FITC
Excitation source: 488 nm spectral line, argon-ion laser
Excitation Wavelength: 488 nm
Emission Wavelength: 535 nm
标记（Labeling）
The primary amines in the side chains of lysine residues and the N-terminus of the protein are conjugated with FITC using standard chemical labeling method. The residual FITC is removed by molecular sieve treatment during purification process.
蛋白标记度（Protein Ratio）
The FITC to protein molar ratio is 2-4.
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.
电泳（SDS-PAGE）
FITC-Labeled SARS-CoV-2 Spike NTD, His Tag on SDS-PAGE under reducing (R) condition. The gel was stained with Coomassie Blue. The purity of the protein is greater than 90%.
活性（Bioactivity）-ELISA
Immobilized Anti-SARS-CoV-2 Spike NTD Antibody, Chimeric mAb, Human IgG1 (Cat. No. SPD-M121) at 1 μg/mL (100 μL/well) can bind FITC-Labeled SARS-CoV-2 Spike NTD, His Tag (Cat. No. SPD-CF2H3) with a linear range of 0.039-2.5 μg/mL (QC tested).
Protocol
背景（Background）
It's been reported that Coronavirus can infect the human respiratory epithelial cells through interaction with the human ACE2 receptor. The spike protein is a large type I transmembrane protein containing two subunits, S1 and S2. S1 mainly contains a receptor binding domain (RBD), which is responsible for recognizing the cell surface receptor. S2 contains basic elements needed for the membrane fusion.The S protein plays key parts in the induction of neutralizing-antibody and T-cell responses, as well as protective immunity.
