Dr. Prasher said his proposal included speculation on how the fluorescent protein might be used as a beacon to light up structures in cells. “That would have certainly been part of my research program,” Dr. Prasher said. “I knew it could serve as a genetic marker and it would be really, really useful, which it has turned out to be.”

That application was turned down. A parallel proposal to the American Cancer Society succeeded, giving Dr. Prasher only two years of financing, enough time to isolate the gene, but not pursue any applications.

By then, however, Dr. Prasher had decided that Woods Hole was not the place for him. Instead of going through the tenure process  he thought he would be turned down, anyway  he looked for a new job. Dr. Chalfie and Dr. Tsien independently contacted Dr. Prasher asking about the jellyfish gene. Dr. Prasher generously shared the gene with both of them.

Dr. Prasher then worked for the United States Department of Agriculture, first on Cape Cod and later in Beltsville, Md., developing methods for identifying pests and other insects. Again, he was not happy, experiencing the beginning of bouts of depression. “I was not happy with management there, so I looked for another position,” he said.

His next move was to Huntsville, where he worked for a NASA subcontractor that was developing mini-chemistry laboratories, which would be needed as health diagnostic tools for a potential human flight to Mars. Dr. Prasher loved that job, but NASA eliminated the financing for the project. For family reasons, he stayed in Huntsville, which restricted his opportunities. “The amount of life science done here is very limited,” he said.