Buy 3 and get the 4th FREE!* | Learn More >>
CD28 (CD28.2) Mouse mAb (PE Conjugate)
Antibody Conjugates

CD28 (CD28.2) Mouse mAb (PE Conjugate) #27826

Reviews ()
Citations (0)
  1. F

Flow cytometric analysis of live human peripheral blood mononuclear cells using CD28/CD28.2 Mouse mAb (PE Conjugate) (solid line) compared to concentration-matched Mouse (MOPC-21) mAb IgG1 Isotype Control (PE Conjugate) #63630 (dashed line).

To Purchase # 27826S
Product # Size Price
500 µl  (100 tests) $ 209

Supporting Data

MW (kDa)
Isotype Mouse IgG1, kappa

Application Key:

  • W-Western
  • IP-Immunoprecipitation
  • IHC-Immunohistochemistry
  • ChIP-Chromatin Immunoprecipitation
  • IF-Immunofluorescence
  • F-Flow Cytometry
  • E-P-ELISA-Peptide

Species Cross-Reactivity Key:

  • H-Human
  • M-Mouse
  • R-Rat
  • Hm-Hamster
  • Mk-Monkey
  • Mi-Mink
  • C-Chicken
  • Dm-D. melanogaster
  • X-Xenopus
  • Z-Zebrafish
  • B-Bovine
  • Dg-Dog
  • Pg-Pig
  • Sc-S. cerevisiae
  • Ce-C. elegans
  • Hr-Horse
  • All-All Species Expected

Product Description

This Cell Signaling Technology antibody is conjugated to PE and tested in-house for direct flow cytometry analysis in human cells.

Product Usage Information

Application Dilution
Flow Cytometry 1:20


Supplied in 10 mM NaH2PO4, 150 mM NaCl, 0.09% NaN3, 0.1% gelatin, pH7.2. This product is stable for 6 months when stored at 4ºC. Do not aliquot the antibody. Protect from light. Do not freeze.



View >Collapse >

Flow Cytometry, Live Cell Protocol for Directly Conjugated Antibodies

A. Solutions and Reagents

NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalent grade water.

  1. 1X Phosphate Buffered Saline (PBS): To prepare 1 L 1X PBS: add 100 ml 10X PBS (#12528) to 900 ml water, mix.
  2. Antibody Dilution Buffer: Purchase ready-to-use Flow Cytometry Antibody Dilution Buffer (#13616), or prepare a 0.5% BSA PBS buffer by dissolving 0.5 g Bovine Serum Albumin (BSA) (#9998) in 100 ml 1X PBS. Store at 4°C.

NOTE: When including fluorescent cellular dyes in your experiment (including viability dyes, DNA dyes, etc.), please refer to the dye product page for the recommended protocol. Visit for a listing of cellular dyes validated for use in flow cytometry.

B. Immunostaining

NOTE: Count cells using a hemocytometer or alternative method.

NOTE: If using whole blood, lyse red blood cells and wash by centrifugation prior to Immunostaining.

NOTE: Optimal centrifugation conditions will vary depending upon cell type and reagent volume. Generally, 150-300g for 1-5 minutes will be sufficient to pellet the cells.

  1. Aliquot desired number of cells into tubes or wells. (Generally, 5x105 to 1x106 cells per assay.)
  2. Pellet cells by centrifugation and remove supernatant.
  3. Resuspend cells in 100 µl of diluted primary antibody, prepared in Antibody Dilution Buffer at a recommended dilution or as determined via titration.
  4. Incubate for 30 min to 1 hr on ice. Protect from light.
  5. Wash by centrifugation in Antibody Dilution Buffer. Discard supernatant. Repeat.
  6. Resuspend cells in 200-500 µl of Antibody Dilution Buffer and analyze on flow cytometer.

posted June 2017

revised August 2019

Protocol Id: 1504

Specificity / Sensitivity

CD28/CD28.2 Mouse mAb (PE Conjugate) recognizes endogenous levels of total CD28 protein. This antibody detects an epitope within the extracellular domain.

Species Reactivity:


Source / Purification

This monoclonal antibody was purified from tissue culture supernatant via affinity chromatography. The purified antibody was conjugated under optimal conditions, with unreacted dye removed from the preparation.


CD28 is a transmembrane glycoprotein expressed by T cells as well as some other hematopoietic cells (1, 2). T cell activation requires T cell receptor (TCR) recognition of antigen presented in the context of MHC molecules. CD28 acts as a T cell costimulatory receptor, and interaction of CD28 with its ligands CD80 or CD86 provides the second signal required for naïve T cell activation (3-5). Activation of naïve T cells in the absence of CD28 stimulation can result in a state of T cell anergy, or unresponsiveness (3). CD28 signals through cytoplasmic phospho-tyrosine motifs that bind several SH2 or SH3 domain-containing proteins involved in T cell activation (2). Recently, CD28 was demonstrated to be a preferred target of PD-1-mediated dephosphorylation. Consistently, CD28 expression was required for T cell proliferation following PD-1 blockade and CD28 stimulation was required for effective anti-PD-1 cancer immunotherapy in mice (6, 7). Several CD28 isoforms are produced by alternative splicing (8).

  1. Aruffo, A. and Seed, B. (1987) Proc Natl Acad Sci U S A 84, 8573-7.
  2. Esensten, J.H. et al. (2016) Immunity 44, 973-88.
  3. Harding, F.A. et al. (1992) Nature 356, 607-9.
  4. Azuma, M. et al. (1993) Nature 366, 76-9.
  5. Linsley, P.S. et al. (1990) Proc Natl Acad Sci U S A 87, 5031-5.
  6. Hui, E. et al. (2017) Science 355, 1428-1433.
  7. Kamphorst, A.O. et al. (2017) Science 355, 1423-1427.
  8. Magistrelli, G. et al. (1999) Biochem Biophys Res Commun 259, 34-7.

Pathways & Proteins

Explore pathways + proteins related to this product.

For Research Use Only. Not For Use In Diagnostic Procedures.

Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.