P{FRT(PT-GFSTF.1)} is a transgenic donor construct containing a recombination-mediated cassette exchange (RMCE) cassette flanked by FRT sites. The RMCE cassette consists of two inverted attB sites which surround a protein trap sequence composed of a splice acceptor, a (GGS)[[4]] flexible linker, the 'GFSTF' multiple tag cassette (EGFP-Tag:CALI(TC) ('FlAsH')-Tag:StrepII-Tag:CS(TEVp)-3xTag:FLAG), another (GGS)[[4]] flexible linker and a splice donor site. A w^+mW.hs marker is located outside of the RMCE cassette, between one of the attB sites and one of the FRT sites. Upon expression of FLP recombinase, the RMCE cassette is released as a circular DNA, which in the presence of phiC31:int integrase can undergo RMCE with a target site containing inverted attP sites, replacing the target 'inverted attP' cassette with the GFSTF protein trap cassette.