In the realm of protein biochemistry, precision is paramount. As an enthusiast who frequently works with affinity purification and epitope tagging, I have spent considerable time analyzing the specifications of the tools I use. One of the most common inquiries I encounter—and one I have researched extensively—concerns the molecular weight of flag peptide. Understanding these metrics is essential for maintaining experimental consistency and ensuring accurate molar calculations during buffer preparation.
Defining the Entity: The FLAG Peptide
The FLAG peptide, widely recognized by its sequence DYKDDDDK, is a s DYKDDDDK (FLAG®) Peptide for Elution ynthetic octapeptide utilized extensively for the purification and detection of recombinant proteins. From my personal experience in the lab, this tag is favored for its high solubility and its lack of interference with the folding or function of the target protein.
When discussing its physical properties, it is critical to distinguish between the standard epitope and the tandem versions. The standard FLAG peptide has a molecular mass (often referred to interchangeably as molecular weight) of approximately 1012.97 Daltons. You will often see this rounded to 1013 or 1013.0 g/mol in various technical datasheets.
Comparative Analysis: Standard vs. 3X FLAG
One common point of confusion for those starting out is the difference between the standard tag and the 3X variant. Based on my review of current specifications:
* Standard FLAG Peptide: Its molar mass is consistently cited around 1012.97 to 1012.99 Da. This small size (approximately 1 kDa) makes it an ideal candidate for fusion proteins where st FLAG Tag Size. The molecular weight of the DYKDDDDK-tag (FLAG-tag) is1012 Da. The multiple polyanionic amino acids in the FLAG tag are less likely to Read more eric hindrance must be minimized.
* 3X FLAG Peptide: This is a more complex synthetic peptide consisting of 23 amino acid residues. Its molar weight is significantly higher, typically listed as 2861.87 or 2864 Da.
When calculating the amount of reagent needed for elution, I always double-check whether I am using the standard or the 3X version. Using the wrong molecular weight in your dilution calculations can drastically alter your elution efficiency.
Practical Considerations for Researchers
When handling these peptide Empirical Formula (Hill Notation):. C41H60N10O ; Molecular Weight:1012.97; UNSPSC Code: 12352202 ; NACRES: NA.32 ; Product Name. FLAG®Peptide, lyophilized powder Read more s, I have found that storage protocols significantly influence the integrity of the material. Most h FLAG peptide - MedchemExpress.com igh-purity synthetic peptides are provided as a lyophilized white powder. To maintain stability, I always store them at -20°C in a desiccated environment.
Regarding solubility, the standard FLAG peptide is highly soluble. I typically prepare stocks in water or 1% acetic acid, ensuring that I reach concentrations of ≥90 mg/mL when necessary for specific affinity purification protocols. If you are working with the Biotin-FLAG peptide, note that the addition of the biotin moiety increases the molecular weight to approximately 1239.26 Da, which must be accounted for in your experimental stoichiometry.
Technical Specifications Summary
To assist fellow researchers, I have compiled the following reference data based on common ind FLAG® Tag Peptide ustry standards:
| Peptide Type | Typical Molecular Weight (Da) |
|---|---|
| Standard FLAG (DYKDDDDK) | 1012.97 |
| 3X FLAG Peptide | 2861.87 |
| Biotin-FLAG Peptide | 1239.26 |
Final Thoughts on Experimental Accuracy
Whether you are performing immunoaffinity DYKDDDDK (FLAG®) Peptide for Elution chromatography or studying protein-protein interactions, having a firm grasp of the molecular weight is the first step in successful experimentation. I have found that by treating these reagents with the same rigor as any other critical component—verifying the molecular mass and ensuring proper storage—one can achieve much more reproducible results.
Always remember to reference the specific Certificate of Analysis provided by your supplier, as slight variations in purity or hydration status can influe FLAG tag Peptide - Versatile Fusion Tag for Protein Research nce the final molar mass calculations. By paying attention to these details, you ensure that your work with the FLAG tag remains both accurate and reliable.