The recombinant RFP (dsRed) was expressed and purified from transformed E. coli using a method that ensures high purity and maximal RFP fluorescence. Endotoxin was removed, so the protein is suitable for in vivo injection or cell culture applications. The protein is a 27.6 kDa monomers containing a N-terminus 6x His-Tag with Ex./Em. = 557/585 nm, extinction coefficient (e 280 nm = 34380 M-1 Cm-1). MW: 27.6 kDa. Purity ≥97%