N-sg100 corresponds to an N-terminal portion (amino acid residues 1-157) of the 'sg100' fluorescent protein (an artificial, enhanced-stability derivative of the Aequorea victoria GFP gene) (PMID:16145770). If the N-sg100 split fluorescent fragment is brought together with a complementary split fluorescent fragment in vivo, a functional fluorescent protein may be reconstituted. N-sg100 is designed for use in the bimolecular fluorescence complementation (BiFC) technique, which is used to study protein-protein interactions in vivo (PMID:11983170).