Anti-DDDDK Tag [Clone 4E11]- Purified No Carrier Protein

Peptide immunogen DYKDDDDK

This monoclonal antibody is aseptically packaged and formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.2 - 7.4 with no carrier protein, potassium, calcium or preservatives added.

Liquid

Purified antibodies are manufactured in an animal free facility using only in vitro protein free cell culture techniques and are purified by a multi-step process including the use of protein A or G to assure extremely low levels of endotoxins, leachable protein A or aggregates.

This antibody may be stored sterile as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at ≤ -70°C. Avoid Repeated Freeze Thaw Cycles.

Research Use Only

Dry 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.