spCFP1-10 is a split fluorescent protein fragment that encodes 10 of the 11 strands of the GFP β-barrel structure. If the spCFP1-10 split fluorescent fragment is brought together with a complementary split fluorescent fragment (e.g. spGFP11) in vivo, a functional fluorescent protein may be reconstituted. spCFP1-10 was derived by mutagenesis of the spGFP1-10 split fluorescent fragment, introducing the mutations Y66W, S72A, N146I and H148D so that the reconstituted fluorescent protein is a Cerulean color variant (FBrf0230337). spCFP1-10 is designed for use in the 'GFP Reconstitution Across Synaptic Partners' (GRASP) technique (PMID:18255029), to study connectivity in the nervous system.