Flag peptide is a commonly used protein tag in the field of life sciences. Molecular biology methods can be used to bind the FLAG tag to the target protein to form a new recombinant protein molecule. This recombinant protein molecule can be combined with an anti-FLAG tag antibody, which can save the cost and effort of designing antibodies specifically for the protein.
Flag peptide is a highly acidic octapeptide with a calcium-dependent epitope for monoclonal antibodies, allowing elution under non-denaturing conditions and can be fused to the N-terminus of the target protein. Flag peptide can be captured by immunoaffinity columns in the presence of Ca2+ and eluted by EDTA at low concentrations and neutral pH (thus close to physiological conditions) .
Purification of reprogramming factors in mammalian cells by FLAG peptide . Transfected cells: HEK293 cells were transfected with FLAG-tagged reprogramming factors and washed twice with PBS 24 h after transfection. Collect cells: Use NP40 cell lysis buffer (50 mM Tris-HCl, pH 7.4, 250 mM NaCl, 5 mM EDTA, 1% NP-40 and protease inhibitors). The cell lysate was centrifuged at 14,500 rpm for 15 min at 4°C and the soluble fraction was collected. Add Anti-Flag Affinity Gel (HY-K0217) to the supernatant and incubate with rotation in a cold room for 16 h. Wash twice with PBS and add 0.1 mg/ml FLAG peptide to elute the retained FLAG-tagged protein. Use dialysis tubing to dialyze the eluted protein in dialysis buffer (PBS).
Sequence: NH2-DYKDDDDK-COOH
Molecular Weight: 1012.96 Da
CAS.NO.:98849-88-8
Format: Lyophilized white powder
QC analysis: Mass Spec and LC-HPLC
Package：10bottles per box
Flag peptide Core functions
1.Immunomodulation: as a vaccine adjuvant to enhance antigen presentation efficiency (such as HPV vaccine development);
2.Targeted delivery: combined with nanocarriers to achieve tumor-specific drug delivery;
3.Antibacterial effect: exerts a broad-spectrum antibacterial effect by destroying pathogen biofilms.
Flag peptide Application market status
1.Medical field (accounting for 65%): used for tumor immunotherapy (global market size of US$1.2 billion in 2024);
2.Scientific research reagents: account for 7.3% of the life science tool market.
Flag peptide Development prospects
1.Technological breakthrough: AI-assisted design will promote the development of the third-generation smart flag peptide;
2.Favourable policy: "14th Five-Year Plan" bio-economy plan lists it as a key protein drug;
Flag peptide Advantages:
1.High Specificity:
Anti-FLAG antibodies bind specifically to the FLAG tag, minimizing non-specific interactions and background.
2.Low Background:
The FLAG peptide is a small, hydrophilic peptide, which minimizes potential interference with protein folding or function.
3.Versatility:
The FLAG peptide can be used in a wide range of applications, including purification, detection, and conjugation.
4.Cleavability:
The FLAG peptide can be removed from the protein of interest using enterokinase, an enzyme that cleaves the peptide bond C-terminal to the tag sequence.
Flag peptide Market forecast: The compound growth rate from 2025 to 2030 is expected to reach 24.7%, and the anti-aging field may become a new growth point.
