Green fluorescent protein (GFP) is composed of 238 amino acids (26.9kDa), and exhibits bright green fluorescence when exposed to blue light. Although many marine organisms have similar green fluorescent proteins, GFP traditionally refers to the protein first isolated from the jellyfish Aequorea victoria. The GFP from A. victoria has a major excitation peak at a wavelength of 395 nm and a minor one at 475 nm. Its emission peak is at 509 nm which is in the lower green portion of the visible spectrum. The GFP from the sea pansy (Renilla reniformis) has a single major excitation peak at 498 nm. In cell and molecular biology, the GFP gene is frequently used as a reporter of expression. In modified forms it has been used to make biosensors, and many organisms have been created that express GFP as a proof-of-concept that a gene can be expressed throughout a given organism. The GFP gene can be introduced into organisms and maintained in their genome through breeding, injection with a viral vector, or cell transformation.
Anti-GFP-SAP is a chemical conjugate of the mouse monoclonal antibody to green fluorescent protein (GFP) and the ribosome-inactivating protein, saporin. It specifically eliminates cells with extracellular expression of GFP-tagged proteins and cells that recognize YOUR GFP-tagged recombinant proteins.