Key Product Details

Species Reactivity

Human

Applications

Flow Cytometry

Label

CoraFluor 1

Antibody Source

Recombinant Monoclonal Rabbit IgG Clone # 2946A

Concentration

Please see the vial label for concentration. If unlisted please contact technical services.

View all CD28 Antibodies »

Product Specifications

Immunogen

S. frugiperda insect ovarian cell line Sf21-derived recombinant human CD28
Asn19-Pro152
Accession # P10747

Specificity

Detects human CD28 in direct ELISA.

Clonality

Monoclonal

Host

Rabbit

Isotype

IgG

Description

CoraFluor(TM) 1 is a high performance terbium-based TR-FRET (Time-Resolved Fluorescence Resonance Energy Transfer) or TRF (Time-Resolved Fluorescence) donor for high throughput assay development. CoraFluor(TM) 1 absorbs UV light at approximately 340 nm, and emits at approximately 490 nm, 545 nm, 585 nm and 620 nm. It is compatible with common acceptor dyes that absorb at the emission wavelengths of CoraFluor(TM) 1. CoraFluor(TM) 1 can be used for the development of robust and scalable TR-FRET binding assays such as target engagement, ternary complex, protein-protein interaction and protein quantification assays.

CoraFluor(TM) 1, amine reactive

CoraFluor(TM) 1, thiol reactive

For more information, please see our CoraFluor(TM) TR-FRET technology flyer.

Scientific Data Images for CD28 Antibody (2946A) [CoraFluor™ 1]

CD28 Antibody (2946A) [CoraFluor™ 1]

Product Feature: CoraFluor Probes for TR-FRET

CoraFluor™ 1, amine reactive (Catalog:7920) and CoraFluor™ 2, amine reactive (Catalog # 7950) are terbium-based probes that have been developed for use as TR-FRET donors. They emit wavelengths compatible with commonly used fluorescent acceptor dyes such as BODIPY® (or BDY) and Janelia Fluor® dyes, FITC (Catalog # 5440), TMR and Cyanine 5 (Catalog # 5436). CoraFluor™ fluorescence is brighter and more stable in biological media than existing TR-FRET donors, leading to enhanced sensitivity and improved data generation. CoraFluor™ 1 exhibits excitation upon exposure to a 337 nm UV laser.

Applications for CD28 Antibody (2946A) [CoraFluor™ 1]

Application
Recommended Usage

Flow Cytometry

Optimal dilutions of this antibody should be experimentally determined.
Application Notes
Optimal dilution of this antibody should be experimentally determined.

Formulation, Preparation, and Storage

Purification

Protein A or G purified from cell culture supernatant

Formulation

PBS

Preservative

No Preservative

Concentration

Please see the vial label for concentration. If unlisted please contact technical services.

Shipping

The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

Stability & Storage

Store at 4C in the dark. Do not freeze.

Background: CD28

CD28 (cluster differentiation 28) is a 44 kDa disulfide linked homodimeric T cell specific surface glycoprotein with a role in providing co-stimulatory signals required for T cell activation and survival (1). The CD28 family of receptors, including PD-1, CTLA-4, and ICOS, share several common features including paired V-set immunoglobulin superfamily (IgSF) domains attached to a single transmembrane domain and cytoplasmic domains containing critical signaling motifs (2). Additionally, CD28 and CTLA-4 are very similar in genomic organization. The corresponding genes co-map on human chromosome 2q33 and mouse chromosome 1 (3). Human CD28 isoform 1 is synthesized as a protein of 220 amino acids (aa) in length with a calculated molecular weight of 25 kDa (3).

CD28 is the prototypical and best-characterized costimulatory molecule on T cells (4). Its signals are critical for optimal naive T cell activation, cytokine production, proliferation, and survival (4). In order to sustain T cell activation, CD28 will consolidate immunological synapse formation, increase cell cycle progression through upregulated D-cyclin expression, and aid in T cell survival by in inducing the expression of the anti-apoptotic protein Bcl-XL (5). CD28 is constitutively expressed on naive and central memory CD4+ and CD8+ cells (5). CD28 deficiency has a large impact on T cell responses including activation, proliferation, immunoglobulin (Ig) class-switching, and germinal center (GC) formation (6). CD28 is a critical regulator of autoimmune diseases and tolerance to solid organ transplants in human patients (6). The CD28 pathway plays a central role in immune responses against pathogens, autoimmune diseases, and graft rejection (7). CD28 engagement via antibodies augments the proliferation of T cells in response to immobilized anti-CD3 antibodies (8). Additionally, antibody engagement of CD28 can supply costimulation to T cells encountering APCs deficient in costimulatory ligands, such as CD80 and CD86, and prevents the resultant anergic state that otherwise occurs in the absence of costimulatory signaling (8).

References

1. Esensten, J. H., Helou, Y. A., Chopra, G., Weiss, A., & Bluestone, J. A. (2016). CD28 Costimulation: From Mechanism to Therapy. Immunity, 44(5), 973-988. https://doi.org/10.1016/j.immuni.2016.04.020

2. Carreno, B. M., & Collins, M. (2002). The B7 family of ligands and its receptors: new pathways for costimulation and inhibition of immune responses. Annual review of immunology, 20, 29-53. https://doi.org/10.1146/annurev.immunol.20.091101.091806

3. Ward S. G. (1996). CD28: a signaling perspective. The Biochemical journal, 318 (Pt 2), 361-377. https://doi.org/10.1042/bj3180361

4. Zhang, R., Huynh, A., Whitcher, G., Chang, J., Maltzman, J. S., & Turka, L. A. (2013). An obligate cell-intrinsic function for CD28 in Tregs. The Journal of clinical investigation, 123(2), 580-593. https://doi.org/10.1172/JCI65013

5. Evans, E. J., Esnouf, R. M., Manso-Sancho, R., Gilbert, R. J., James, J. R., Yu, C., Fennelly, J. A., Vowles, C., Hanke, T., Walse, B., Hunig, T., Sorensen, P., Stuart, D. I., & Davis, S. J. (2005). Crystal structure of a soluble CD28-Fab complex. Nature immunology, 6(3), 271-279. https://doi.org/10.1038/ni1170

6. Bour-Jordan, H., & Blueston, J. A. (2002). CD28 function: a balance of costimulatory and regulatory signals. Journal of clinical immunology, 22(1), 1-7. https://doi.org/10.1023/a:1014256417651

7. Krummel, M. F., & Allison, J. P. (1995). CD28 and CTLA-4 have opposing effects on the response of T cells to stimulation. The Journal of experimental medicine, 182(2), 459-465. https://doi.org/10.1084/jem.182.2.459

8. Luhder, F., Huang, Y., Dennehy, K. M., Guntermann, C., Muller, I., Winkler, E., Kerkau, T., Ikemizu, S., Davis, S. J., Hanke, T., & Hunig, T. (2003). Topological requirements and signaling properties of T cell-activating, anti-CD28 antibody superagonists. The Journal of experimental medicine, 197(8), 955-966. https://doi.org/10.1084/jem.20021024

Alternate Names

CD28

Additional CD28 Products

Product Documents for CD28 Antibody (2946A) [CoraFluor™ 1]

Product Datasheets

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Download SDS

Product Specific Notices for CD28 Antibody (2946A) [CoraFluor™ 1]

CoraFluor (TM) is a trademark of Bio-Techne Corp. Sold for research purposes only under agreement from Massachusetts General Hospital. US patent 2022/0025254

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Primary Antibodies are guaranteed for 1 year from date of receipt.

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