Spark Blue™ 550 anti-human CD28 (Flexi-Fluor™) Antibody

Product Details

Verified Reactivity

Human

Antibody Type

Monoclonal

Host Species

Mouse

Immunogen

Human CD28 transfected cells

Formulation

Phosphate-buffered solution, pH 7.2, containing 0.09% sodium azide

Preparation

The antibody was purified by affinity chromatography and conjugated with Spark Blue™ 550 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.

Excitation Laser

Blue Laser (488 nm)

Application Notes

Clone S20013B antibody can completely block the binding of clone CD28.2 on target.

Clone S20013B can partially block Clone S20013F on target.

Clone S20013B can increase anti-CD3 induced human peripheral T-cell proliferation.

Clone S20013B is a superagonistic antibody raised towards human CD28, and can induce activation, proliferation of human peripheral T cells without anti-CD3 stimulation.

Additional Product Notes

For more information about Flexi-Fluors™, visit our Flexi-Fluor™ page and review FAQs associated with this product line.

Antigen Details

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

Lymphocytes, T cells, Tfh, Th1, Th17, Th2, Thymocytes, Tregs

Biology Area

Adaptive Immunity, Cell Proliferation and Viability, Costimulatory Molecules, Immuno-Oncology, Immunology

Molecular Family

CD Molecules

Antigen References

1. Schlossman S, et al. Eds. 1995. Leukocyte Typing V. Oxford University Press. New York.
2. June CH, et al. 1994. Immunol Today. 15:321-31.
3. Linsley PS and Ledbetter JA. 1993. Annu Rev Immunol. 11:191-212.

Gene ID

940 View all products for this Gene ID

UniProt

View information about CD28 on UniProt.org

Documentation

• Technical data sheet
• Certificate of Analysis
• Safety Data Sheet

Reviews

Related Protocols

• Cell Surface Flow Cytometry Staining Protocol

Related Pages & Pathways

Related FAQs

What are Flexi-Fluors?

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. 

How quickly will I receive my order?

We aim to ship Flexi-Fluors within 2-3 weeks of receipt of your order. However, depending on your location, shipping times may vary. 

How are Flexi-Fluors different from regular catalog products?

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.

How do I determine the optimal concentration for using my Flexi-Fluor? How should I titrate my antibody?

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. 

I can’t find the antibody-dye combination that I need. When will it be available?

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. 

I need help to validate the performance of my Flexi-Fluor. Who should I contact?

Please get in touch with Technical Service for assistance. 

Can I order more than 50 μg of a Flexi-Fluor?

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.

What is the expiration date of my Flexi-Fluor?

Expiration dates can be found on the vial label or by using our CoA lookup tool. 

Other Formats

Certificate of Analysis