Studies of protein properties, expression, transport, degradation and their interactions with other cellular systems are integral to biomedical research, drug discovery and developmental biology. Eukaryotic proteins function in signaling pathways, metabolism, structure, adhesion, cell movement, active and passive transport, DNA repair, viral disease mechanisms, the immune system, fertilization, differentiation, epigenetics, cancer and the cell division cycle.

For efficient analysis of cellular protein interactions and expression, target genes are often engineered into reporter systems, and then expressed in cells as recombinant fusion proteins. Reporter gene characteristics are chosen to enable downstream in vitroor in vivo method applications. This commonly used and widely successful strategy can facilitate applications such as flow cytometry, cell sorting, in vitro or in vivo imaging, proteomic microarray, cell-based microarray, SDS-PAGE gel electrophoresis, Western blot, quantitative affinity purification followed by mass spectrometry (q-AP-MS), pulse-chase and receptor internalization assays. In particular, improved reporter systems in conjunction with optical imaging technical advances are pushing the frontiers of fluorescence imaging applications.

New England Biolabs offers an innovative technology for studying the function and localization of proteins in living and fixed cells. Covalent protein labeling offers simplicity and versatility to the imaging of mammalian proteins in live cells, as well as the ability to capture proteins in vitro. A single genetic construct generates a fusion protein which, when covalently attached to a variety of fluorophores, biotin or beads, provides a powerful tool for studying protein dynamics. In the first system, the protein is labeled by a self-labeling fusion protein; SNAP-tag^® or CLIP-tag™.

SNAP-tag^® is a registered trademark of New England Biolabs, Inc.