Description: This 5F12.4 monoclonal antibody reacts with green-fluorescent protein (GFP), which was originally isolated from the cnidarian Aequorea victoria. This protein absorbs blue light (maximally at 395 nm) and emits green light (peak at 509) without the requirement of exogenous substrates and cofactors. 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 wildtype GFP, making them useful for flow cytometry, fluorescence microscopy, and double-labeling applications. This antibody is capable of staining formaldehyde fixed cells.