Fusion Tag

Fusion Tag designates short peptide or protein sequences genetically attached to recombinant proteins to facilitate expression, purification, detection, or solubility enhancement. Common tags include His-tags for affinity purification, GST tags improving solubility, and FLAG tags enabling immunodetection. Fusion tags can simplify manufacturing workflows and accelerate research by enabling rapid purification and characterisation of target proteins.

The biopharmaceutical industry uses fusion tags extensively in early research and process development, though therapeutic products typically require tag removal to avoid immunogenicity risks. Tag design must ensure minimal disruption to protein folding and biological activity, with cleavage sites incorporated for enzymatic removal when required. Purification strategies exploit tag-specific affinity resins improving efficiency and yield during development. Analytical methods confirm tag presence or successful removal, supporting product characterisation and comparability. As recombinant protein production expands and rapid prototyping becomes increasingly important, fusion tag strategies remain valuable tools enabling efficient expression and purification.