Description: The polyclonal antibody reacts with GFP; it was raised against a peptide mapping near the carboxy terminus of aequorea victoria GFP. Green fluorescent protein was originally cloned from the cnidarian, Aequorea victoria. This exceptional protein absorbs blue light (maximally at 395 nm) and emits green light (peak at 509 nm) without the requirement of exogenous substrates and cofactors (1). These unique qualities allow GFP to be used to monitor gene expression and protein localization in vivo. Several mutant forms of GFP have been developed which fluoresce more intensely and have shifted excitation maxima when compared to the wild type GFP, making them useful for FACS, fluorescence microscopy, and double-labeling applications (2,3).