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CD4 Fab-Strep, human

Low affinity Fab fragment fused to a Twin-Strep-tag® and specific for human CD4
CD4 Fab-Strep is a recombinantly expressed low affinity Fab fragment fused to a Twin-Strep-tag®. Fab-Streps were developed for Traceless Affinity Cell Selection (Fab-TACS®), which is based on our Strep-tag® technology. Due to their low affinity for the target, an increase in avidity is required to ensure sufficient binding to the cell surface. Combining Fab-Streps with a Strep-Tactin® backbone leads to the formation of complexes that stably bind to cells.

Depending on the Strep-Tactin® backbone, the following applications are possible:
• Fluorescent cell staining & sorting: Fab-Streps are combined with fluorophore-conjugated Strep-Tactin®.
• Magnetic cell isolation: Fab-Streps are combined with Strep-Tactin® Magnetic Microbeads.
• Affinity chromatographic cell isolation: Fab-Streps are loaded in Strep-Tactin® TACS Agarose columns.

By addition of biotin, the labeling reagents dissociate mildly and rapidly from the selected target cells in all applications, yielding minimally manipulated cells for unbiased further use.


Endotoxin Level: ≤ 0.1 EU/µg by LAL test
Form: Lyophilized
Possible Application: Fluorescent cell staining & sorting, magnetic or affinity chromatographic cell isolation
Purity: ≥ 90%
Reconstitution: Reconstitute in 1 ml buffer, e.g. 1x PBS containing 1 mM EDTA and 0.5% BSA, for a final concentration of 50 µg/ml.
Accessories: Fab-Streps

Shipping information

Storage: 2-8 °C; reconstituted: -80 °C
Stability: 6 months after shipping
Shipping: Room temperature or blue ice


Strep-Tactin® TACS Agarose Column
Content: 0.3 ml
Gravity flow column suitable for traceless affinity cell and exosome isolation
Strep-Tactin® PE
Fluorophore-conjugated Strep-Tactin® for cell staining
Strep-Tactin® TACS Agarose
Content: 4 ml
50% suspension for traceless affinity cell and exosome isolation