Anti-DDDDK Tag [Clone 4E11] – HRP

Peptide immunogen DYKDDDDK

This HRP-conjugated antibody is formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.2 - 7.4, 1% BSA. (Warning: Use of sodium azide as a preservative will inhibit the enzyme activity of horseradish peroxidase)

Liquid

This horseradish peroxidase conjugated monoclonal antibody is stable when stored at 2-8°C. Do not freeze.

Research Use Only

2 - 8°C Wet Ice

4E11 activity is specific to the FLAG tag DYKDDDDK.

The FLAG tag is a chemical biology tool designed for protein identification and purification¹. The monoclonal antibody 4E11, also known as M1, is the original anti-FLAG antibody. 4E11 binding is calcium-dependent^1,2,3 and occurs at the very N-terminus of the mature protein¹. Specifically, the 4E11 antibody binds to the DYK at the N terminus. Chelating agents such as EDTA can be used to dissociate the antibody from the antigen, a feature exploited by the design of immunoprecipitation columns^2,3. 4E11 is considered a mild purification reagent for FLAG- epitope tagged fusion proteins².

4E11 was generated by immunizing a BALB/c mouse with the peptide immunogen DYKDDDDK⁴. Spleen cells were fused with NS1 myeloma cells for hybridoma production. 4E11 was isolated by screening for binding to the DYKDDDDK tag fused to the N-terminus of human interleukin-2. 4E11 does not bind MDFKDDDDK or MDYKAFDNL⁵.

FLAG® is a registered trademark of Sigma-Aldrich Co. LLC.

FLAG tags are added to proteins as a biochemical tool to detect or purify the fusion proteins via immunoprecipitation, Western blotting, immunocytochemistry, chromatin IP, immunohistochemistry, and other applications.

1 Beugelink JW, Sweep E, Janssen BJC, et al. J Mol Biol. 436(16):168649. 2024.
2 Hopp TP, Gallis B, Prickett KS. Mol Immunol. 33(7-8):601-608. 1996.
3 Einhauer A, Jungbauer A. J Chromatogr A. 921(1):25-30. 2001.
4 https://patents.google.com/patent/US4851341A/en
5 Slootstra JW, Kuperus D, Plückthun A, et al. Mol Divers. 2(3):156-164. 1997.
6 Pöhner C, Hilbrig F, Jérôme V, et al. Biotechnol Prog. 22(4):1170-1178. 2006.