Green fluorescent protein (GFP)is a 27 kDa protein derived from Aequorea victoria. It absorbs light in the ultraviolet to blue range and emits green (peak emission 510 nm). GFP is a common reporter molecule for protein expression and visualization of intracellular processes. For those employing GFP as a fusion tag, GFP-agarose conjugate may be used to remove potentially confounding GFP binding proteins.