Ten copies of the UAS regulatory sequence drive expression of a non-fluorescent 'spaghetti monster GFP' ('smGdP') marker which consists of 10 copies of the Tag:HA tag inserted in groups into the backbone of the superfolder green fluorescent protein, which has been rendered non-fluorescent by mutation. A N-terminal myristoylation signal (Tag:Myr(Src64B)) is also present, to target the protein to the plasma membrane, and the marker has been optimised for Drosophila codon usage.