FLAG Antibody, IgG2b

The FLAG peptide is a widely used fusion tag in molecular biology and biochemistry. It consists of eight amino acids: Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys (DYKDDDDK). This peptide is specifically designed for immunoaffinity chromatography, allowing for the purification and detection of recombinant fusion proteins under non-denaturing conditions .

The FLAG peptide includes an enterokinase-cleavage site, which facilitates the removal of the tag from the fusion protein if necessary. The hydrophilic nature of the FLAG peptide ensures that it is likely to be located on the surface of the fusion protein, making it accessible to antibodies .

The FLAG peptide is highly versatile and is used in various applications, including:

• Western Blotting: Detecting proteins separated by gel electrophoresis.
• Immunocytochemistry: Visualizing the localization of proteins within cells.
• Immunoprecipitation: Isolating proteins from a mixture using an antibody.
• Flow Cytometry: Analyzing the physical and chemical characteristics of cells or particles.
• Protein Purification: Isolating recombinant proteins from a mixture.
• Protein-Protein Interaction Studies: Investigating interactions between proteins.
• Cell Ultrastructure Studies: Examining the detailed structure of cells.
• Protein Localization Studies: Determining the specific location of proteins within cells .

Several monoclonal antibodies have been developed against the FLAG peptide. One such antibody, denoted as M1, binds the peptide in the presence of bivalent metal cations, preferably calcium. Elution can be achieved using chelating agents or by competitive elution with an excess of free FLAG peptide .

The FLAG peptide mouse antibody, IgG2b, is a monoclonal antibody produced by immunizing mice with the synthetic FLAG peptide coupled to keyhole limpet hemocyanin (KLH). This antibody is used in various laboratory research applications and is not intended for use as a drug, agricultural product, food additive, or household chemical .