Science, 263, 802-805, 1994.
Chalfie (Nobel Prize 2008) and colleagues showed that the green fluorescent protein (GFP) from the jellyfish Aequorea victoria, could be used as a visible marker for protein localization and expression in vivo, in bacteria and worm cells, and in the absence of any contributing factors from the jelly fish itself, proving that the protein acted totally alone without any interference from possible contaminating factors. This demonstration established GFP as a fine tool to study proteins in vivo, and fundamentally altered the way in which investigators could define and study intracellular and intra organismal biological events. Douglas Prasher played a key role in this discovery, but did not share in the Nobel Prize.
About Prasher the Wikipedia article states, "He is known for his work to clone and sequence the genes for the photoprotein aequorin and green fluorescent protein (GFP)  and for his proposal to use GFP as a tracer molecule. He communicated his pioneering work to Martin Chalfie and Roger Y. Tsien, but by 1991 was himself unable to obtain further research funding, and left academia. Eventually, he had to abandon science. Chalfie and Tsien were awarded the 2008 Nobel Prize in Chemistry for work that they publicly acknowledged was substantially based on the work of Douglas Prasher, and through their efforts and those of others, Douglas Prasher returned to scientific research work [in Tsien's laboratory] in June 2010."
Order of authorship in the original paper: Chalfie, Tu, Euskirchen, Ward, Prasher.
(Thanks to Juan Weiss for this reference and its interpretation.)
Subjects: BIOCHEMISTRY › Bioluminescence, BIOLOGY › MOLECULAR BIOLOGY › Protein Structure, BIOLOGY › MOLECULAR BIOLOGY › Protein Synthesis