To confirm that the protein was responsible not just for regulating growth but for all activities set by the biological clock, Pin-Ju Chueh, then a microbiology graduate student in Dorothy Morre's lab, isolated the gene which produced the protein within cells. The team then cloned the protein and altered it in ways that produced different period lengths.Link Discuss (via Schism Matrix)
"We found that we could produce clocks with cycles of between 22 and 42 minutes," James Morre said. "The 'day' which the cell experienced was precisely 60 times the period length of the protein's cycle. We even found that feeding cells heavy water gave them a 27-minute cycle of growth and rest, so that old piece of information served to confirm our theory."