Biolegend, 285434, Spark YG™ 593 anti-human CD28 (Flexi-Fluor™) Antibody, 50μg

CD28 is a 44 kD disulfide-linked homodimeric type I glycoprotein. It is a member of the immunoglobulin superfamily and is also known as T44 or Tp44. CD28 is expressed on most T lineage cells, NK cell subsets, and plasma cells. CD28 binds both CD80 and CD86 using a highly conserved motif MYPPY in the CDR3-like loop. CD28 is considered a major co-stimulatory molecule, inducing T lymphocyte activation and IL-2 synthesis, and preventing cell death. In vitro studies indicate that ligation of CD28 on T cells by CD80 and CD86 on antigen presenting cells provides a costimulatory signal required for T cell activation and proliferation.
50μg
Verified Reactivity: Human
Reported Reactivity: Baboon, Capuchin Monkey, Chimpanzee, Pigtailed Macaque, Sooty Mangabey, Squirrel Monkey
Antibody Type: Monoclonal
Host Species: Mouse
Formulation: Phosphate-buffered solution, pH 7.2, containing 0.09% sodium azide
Preparation: The antibody was purified by affinity chromatography and conjugated with Spark YG™ 593 under optimal conditions.
Concentration: 0.2 mg/mL
Storage & Handling: The antibody solution should be stored undiluted between 2°C and 8°C, and protected from prolonged exposure to light. Do not freeze.
Application: FC
Recommended Usage: Flexi-Fluors™ are provided at a standard 0.2 mg/mL concentration. We recommend titrating this reagent to determine the optimal concentration for each application. For many flow cytometry applications, conjugated antibodies perform well at concentrations ranging from 0.03 to 1.0 µg per million cells in 100 µL. We recommend testing a range of concentrations starting from 10 µg/mL. For example, make five 1:1 serial dilutions of the 0.2 mg/mL antibody. Add 5 µL of each dilution (including the undiluted antibody) to 100 µL of cells (at 107 cells/mL) to test six concentrations -- 1.0, 0.5, 0.25, 0.125, 0.06, and 0.03 µg per million cells in 100 µL volume. Compare staining patterns or create a titration curve using the MFI or staining index to determine the optimal concentration.* Spark YG™ 593 has a maximum excitation of 573 nm and a maximum emission of 593 nm.
Excitation Laser: Green Laser (532 nm)/Yellow-Green Laser (561 nm)
Application Notes: The Ultra-LEAF™ Purified antibody (Endotoxin < 0.01 EU/µg, Azide-Free, 0.2 µm filtered) is recommended for highly sensitive assays.
Additional Product Notes: For more information about Flexi-Fluors™, visit our Flexi-Fluor™ page and review FAQs associated with this product line.
Application References(PubMed link indicates BioLegend citation): Schlossman S, et al. Eds. 1995. Leucocyte Typing V. Oxford University Press. New York. Nunes J, et al. 1993. Biochem. J. 293:835. Calea-Lauri J, et al. 1999. J. Immunol. 163:62. Tazi A, et al. 1999. J. Immunol. 163:3511. (IHC) Marti F, et al. 2001. J. Immunol. 166:197. (Costim) Jeong SH, et al. 2004. J. Virol. 78:6995. (Costim) Rivollier A, et al. 2004. Blood 104:4029. (Costim) Scharschmidt E, et al. 2004. Mol. Cell Biol. 24:3860. (Costim) Sheng W, et al. 2007.Elsevier 580:6819. PubMed Mitsuhashi M. 2007. Clin Chem.53:148. PubMed Ye Z, et al. 2008. Infect. Immun. 76:2541. PubMed Magatti M, et al. 2008. Stem Cells 26:182. (FA) PubMed Yoshino N, et al. 2008. Exp. Anim. (Tokyo) 49:97. (FC) Berg M, et al. 2008. J Leukoc Biol. 83:853. (IP) PubMed Rout N, et al. 2010. PLoS One 5:e9787. (FC) Leonard JA, et al. 2011. J. Virol. 85:6867. PubMed Nomura T, et al. 2012. J. Virol. 86:6481. PubMed
RRID: AB_3716992 (BioLegend Cat. No. 285434)
Structure: Ig superfamily, type I transmembrane glycoprotein, homodimer, 44 kD
Distribution: Mature T cells, thymocytes, NK cell subsets, plasma cells, EBV-positive B cells
Function: T cell costimulation
Ligand/Receptor: CD80, CD86
Cell Type: B cells, NK cells, Plasma cells, T cells, Thymocytes, Tregs
Biology Area: Costimulatory Molecules, Immunology
Molecular Family: CD Molecules
Antigen References: 1. Schlossman S, et al. Eds. 1995. Leucocyte Typing V. Oxford University Press. New York. 2. June CH, et al. 1994. Immunol. Today 15:321. 3. Linskey PS, et al. 1993. Annu. Rev. Immunol. 11:191.
Gene ID: NA
UniProt: View information about CD28 on UniProt.org
Clone: CD28.2
Regulatory Status: RUO
Workshop: V-CD28.05
Other Names: T44, Tp44
Isotype: Mouse IgG1, κ
Q: What are Flexi-Fluors?
A: Flexi-Fluors are rapidly made-to-order conjugated antibodies. The technology, manufacturing processes, and specifications used to create Flexi-Fluors are the same as our regular catalog products. However, the optimal concentration and performance of each Flexi-Fluor must be determined by the customer.
Q: How quickly will I receive my order?
A: We aim to ship Flexi-Fluors within 2-3 weeks of receipt of your order. However, depending on your location, shipping times may vary.
Q: How are Flexi-Fluors different from regular catalog products?
A: Flexi-Fluors are made on demand, specifically for you. Flexi-Fluors are manufactured using the same high-quality standards, and specifications as other catalog products. For faster delivery, Flexi-Fluors are not tested by flow cytometry to determine optimal concentrations or evaluate performance. This testing needs to be performed by the customer.
Q: How do I determine the optimal concentration for using my Flexi-Fluor? How should I titrate my antibody?
A: Flexi-Fluors are provided at a standard 0.2 mg/mL concentration. We recommend that you titrate your antibody to determine the optimal concentration to use for your application. For many flow cytometry applications, conjugated antibodies perform well at concentrations ranging from 0.03 to 1.0 µg per million cells in 100 µL volume. We recommend that you test a range of concentrations starting from 10 µg/mL. 

For example, make five 1:1 serial dilutions of your 0.2 mg/mL antibody.  Add 5 µL of each dilution (including the undiluted antibody) to 100 µL of cells (at 107 cells/ml) to test six concentrations - 1.0, 0.5, 0.25, 0.125, 0.06, and 0.03 µg per million cells in 100 µL volume. Compare staining patterns or create a titration curve using the MFI or staining index to determine the optimal concentration.
Q: I can’t find the antibody-dye combination that I need. When will it be available?
A: We continuously update our catalog, introducing scores of new products every month. Please get in touch with our Technical Service team for an update on new products or recommendations for suitable alternatives to complete your panel. Or contact Custom Solutions to inquire about our affordable custom conjugation services.
Q: I need help to validate the performance of my Flexi-Fluor. Who should I contact?
A: Please get in touch with Technical Service for assistance.
Q: Can I order more than 50 μg of a Flexi-Fluor?
A: Yes, you can order multiple vials of the same Flexi-Fluor products.  We cannot guarantee, however, that these vials will be bottled from the same lot. For bulk single-lot orders, contact our Custom Solutions team.
Q: What is the expiration date of my Flexi-Fluor?
A: Expiration dates can be found on the vial label or by using our CoA lookup tool.
Q: What if my requested antibody-dye combination doesn't perform as expected?
A: Flexi-Fluor™ products have been carefully selected by our scientists for their excellent conjugation properties and broad compatibility. In the rare case that an antibody-dye combination does not perform as expected due to the unique characteristics of a specific pairing, please contact our Technical Service team. We will work with you to identify alternative options to meet your panel requirements.