NEW Anti-FLAG Biosensors for FLAG-tagged Biomolecule Analysis

Darick Dayne, PhD, Senior Product Manager,

Continuing on an unprecedented record of technological innovation, ForteBio is excited to announce the launch of our Anti-FLAG Biosensor. The FLAG® polypeptide tag (DYKDDDDK) was one of the first examples of a fully functional tag to be published. The FLAG tag's structure was more optimized for compatibility with attached proteins and is more hydrophilic than other common tags and therefore less likely to denature or inactivate its attached proteins. Because of its functional advantages, the FLAG tag is commonly used in industry to facilitate the detection and purification of recombinant proteins.

Pre-immobilized with the highly specific ANTI-FLAG M2® antibody from Sigma, our new Anti-FLAG Biosensor further extends the capabilities of the Octet and BLItz platforms to enable fast and easy analysis of FLAG-tagged proteins. Its high specificity allows the capture of FLAG-tagged proteins directly from unpurified crude samples while enabling high throughput measurements of FLAG-tagged protein concentrations.

The Anti-FLAG Biosensor offers researchers an unprecedented ease of use and time-to-result in a wide range of laboratory applications. Kinetic measurements for KD determination between FLAG fusion proteins and binding partners, efficient workflows for epitope binning, process optimization in development and quality control, and high throughput titer

measurements of FLAG-tagged protein production are now made easier than ever.

For more information, please contact your local ForteBio representative or visit to download the datasheet and technical notes.

FLG Kinetic Analysis

Figure 1: Kinetic analysis of the interaction between ligand TRAIL-FLAG (23 kDa) and an analyte mouse anti-TRAIL (150 kDa). 10X kinetics buffer was used as the matrix throughout and the assay temperature was 30°C. Data were processed and the curve fit using a 1:1 binding model. The kinetic results are reported in Table 1.

kon koff KD
1.20E+05 1/Ms 2.56E-05 1/s 2.13E-10 M

Table 1: Kinetic results for the interaction between ligand TRAIL-FLAG (23 kDa) and an analyte mouse anti-TRAIL (150 kDa) using Anti-FLAG biosensors.