Fassisi has within a two years research project with partners developed the next generation of lateral flow test systems using the patented Strep-tag technology.

Using this technology, highest sensitivities and specificities with lateral flow assay can be achieved.


How does the Fassisi-tag work

The Fassisi-tag is used in a sandwich immuno-assay.


Technical background on the Fassisi-tag

The Strep-tag system is since the beginning of the 1990s a recognized method that has been successfully used in the affinity- chromatographic purification of proteins . The Strep-tag technology has its origins in the strong binding affinity of the proteins streptavidin and biotin :

Streptavidin is produced by the bacterium Streptmyces avidinii and has an extremely high binding affinity for vitamin D ( biotin) . This high binding affinity between streptavidin and biotin has been used for decades routinely in biotechnology for the detection and signal amplification in enzyme-linked immunosorbent assays (ELISA).

Since the beginning of the 1990s this system has been optimized and from the binding partners biotin - streptavidin the peptides (Strep-tag)-(Strep-Tactin )  were developed.
Strep tag is a synthetic peptide of the biotin, which consists of eight amino acid, and has an extremely strong binding affinity for the Strep-Tactin, a synthetic derivative of streptavidin. Strep-tag may be coupled to both the N- as well as to the C -terminal end of proteins, without altering their biological properties.

This extremely strong bond between Strep-tag and Strep-Tactin is used among other things to purify Strep- tag coupled, recombinant proteins, even from cell mixtures completely, under physiological conditions.

The Fassisi-tag implements these characteristics into a lateral flow assay.