分子别名（Synonym）
CD28,Tp44
表达区间及表达系统（Source）
Biotinylated Human / Cynomolgus / Rhesus macaque CD28, Fc,Avitag (CD8-H82F2) is expressed from human 293 cells (HEK293). It contains AA Asn 19 - Pro 152 (Accession # AAH93698). In the region Asn 19 - Pro 152, the AA sequence of Human, Cynomolgus and Rhesus macaque CD28 are homologus.
Predicted N-terminus: Asn 19
蛋白结构（Molecular Characterization）
This protein carries a human IgG1 Fc tag at the C-terminus, followed by a Avi tag (Avitag™).
The protein has a calculated MW of 43.6 kDa. The protein migrates as 55-66 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.
标记（Biotinylation）
Biotinylation of this product is performed using Avitag™ technology. Briefly, the single lysine residue in the Avitag is enzymatically labeled with biotin.
蛋白标记度（Biotin:Protein Ratio)
The biotin to protein ratio is 0.5-1 as determined by the HABA assay.
内毒素（Endotoxin）
Less than 1.0 EU per μg by the LAL method.
纯度（Purity）
>95% as determined by SDS-PAGE.
制剂（Formulation）
Lyophilized from 0.22 μm filtered solution in Tris with Glycine, Arginine and NaCl, pH7.5. Normally trehalose is added as protectant before lyophilization.
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 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）
Biotinylated Human / Cynomolgus / Rhesus macaque CD28, Fc,Avitag on SDS-PAGE under reducing (R) condition. The gel was stained overnight with Coomassie Blue. The purity of the protein is greater than 95%.
活性（Bioactivity）-ELISA
Immobilized Biotinylated Human / Cynomolgus / Rhesus macaque CD28, Fc,Avitag (Cat. No. CD8-H82F2) at 1 μg/mL (100 μL/well) on Streptavidin (Cat. No. STN-N5116) precoated (0.5 μg/well) plate, can bind Human B7-1, Mouse IgG2a Fc Tag, low endotoxin (Cat. No. B71-H52A4) with a linear range of 5-78 ng/mL (QC tested).
Protocol
Immobilized Anti-CD28 MAb, Mouse IgG1 at 5 μg/mL (100 μL/well) can bind Biotinylated Human / Cynomolgus / Rhesus macaque CD28, Fc,Avitag (Cat. No. CD8-H82F2) with a linear range of 2.4-39 ng/mL (Routinely tested).
Protocol
Immobilized Human B7-1, Fc Tag (Cat. No. B71-H5259) at 5 μg/mL (100 μL/well) can bind Biotinylated Human / Cynomolgus / Rhesus macaque CD28, Fc,Avitag (Cat. No. CD8-H82F2) with a linear range of 0.313-5 μg/mL (Routinely tested).
Protocol
文献引用（Citations）
Authors: G Aravindhan, et al.
Journal: BBA-GEN SUBJECTS 2018
Application: ELISA
背景（Background）
T-cell-specific surface glycoprotein CD28 is also known as TP44, is a single-pass type I membrane protein which contains one Ig-like V-type (immunoglobulin-like) domain. is one of the molecules expressed on T cells that provide co-stimulatory signals, which are required for T cell activation. CD28 is the receptor for CD80 (B7.1) and CD86 (B7.2). When activated by Toll-like receptor ligands, the CD80 expression is upregulated in antigen presenting cells (APCs). The CD86 expression on antigen presenting cells is constitutive. CD28 is the only B7 receptor constitutively expressed on naive T cells.
