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T cell stimulation & expansion

Key features:

In contrast to other existing expansion systems,

  • with the CD3/CD28 Streptamers® for T cell expansion the stimulation of T cells can be stopped at any time. Simply add biotin to the medium. The stimulation state of the cells can thus be precisely controlled and the cell receptors are available for further staining experiments;
  • with the Streptamer® CD3/CD28 Kit for T cell expansion you can modify the CD3 : CD28 Fab-Strep ratio according to your needs, or just follow our recommendations;

Get unmanipulated naturally occurring T cells for your research with the Streptamer® technology!

T cell stimulation

Naive T cells require at least two signals for activation, proliferation and differentiation. The first signal is generated via the T cell receptor (TCR) and its MHC ligand. The second, most effective co-stimulatory signal is evoked by the interaction of the CD28 receptor of the T cell with its ligand CD80/86 (glycoprotein B7).



CD3/CD28 Streptamers® for T cell expansion

The Streptamers® for cell expansion are novel reagents for polyclonal expansion of T cells:

They are non-magnetic soluble protein complexes generated by multimerization of αCD3- and αCD28 Fab-Streps with a Strep-Tactin® multimer. They are completely reversible reagents, i.e. they can be removed from the cells by the addition of biotin.

Reaction scheme of CD3/CD28 Streptamers® for T cell expansion

CD3- and CD28 Fab-Streps are multimerized via the soluble Strep-Tactin® multimere to generate the soluble Streptamer® for cell expansion. The subsequent biotin-induced dissociation of the reagents from the cells can be performed at any time point during stimulation, simply by the addition of biotin. The termination of stimulation can thus be precisely controlled.

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Streptamers® for T cell expansion


  1. Bashour, K.T., Larson, R.P., Graef, P., Stemberger, C., Germeroth L., Odegard, V. and Ramsborg, C.G. (2015) Functional characterization of a T Cell Stimulation Reagent for the Production of Therapeutic Chimeric Antigen Receptor Cells. ASH 57th Annual Meeting & Exposition, Orlando, FL
  2. Wang, X. and Rivière, I. (2016) Clinical manufacturing of CAR T cells: foundation of a promising therapy. Molecular Therapy - Oncolytics 3, 16015
  3. Poltorak M. P., Graef P., Tschulik C., Wagner M., Cletiu V., Dreher S., Borjan B., Fraessle S. P., Effenberger M., Turk M., Busch D. H., Plitzko J., Kugler D. G., Ragan S., Schmidt T., Stemberger C., Germeroth L. (2020) Expamers: a new technology to control T cell activation. Scientific Reports volume 10, Article number: 17832 (2020)