Auto-induction protein production

Credit: Omikron / Photo Researchers, Inc" /> Credit: Omikron / Photo Researchers, Inc The paper: F.W. Studier, "Protein production by auto-induction in high-density shaking cultures," Protein Express Purif, 41:207-34, 2005. (Cited in 124 papers) The finding: While working on the National Institutes of Health's structural genomics project, William Studier at the Brookhaven National Laboratory devised a method that produced up to 10 times the protein

Nov 1, 2007
Andrea Gawrylewski
<figcaption> Credit: Omikron / Photo Researchers, Inc</figcaption>
Credit: Omikron / Photo Researchers, Inc

The paper:
F.W. Studier, "Protein production by auto-induction in high-density shaking cultures," Protein Express Purif, 41:207-34, 2005. (Cited in 124 papers)

The finding:
While working on the National Institutes of Health's structural genomics project, William Studier at the Brookhaven National Laboratory devised a method that produced up to 10 times the protein yields of conventional techniques and induced simultaneous expression in Escherichia coli cells.

The method:
Studier grew the cells in sync by blocking the entrance of lactose into the cells with glucose until the cells reached a certain growth. Once cells consume the glucose, lactose enters the cells and allows induction of proteins. "It's a great timesaver," Studier says.

The fine-tuning:
"You can manipulate the medium and by doing that change expression level," says Brian Fox from the University of Wisconsin, who uses the auto-induction technique in his work on enzymes. "The original Studier medium is 0.2% weight-to-volume lactose, and about 0.2% to 0.3% weight-to-volume glycerol. We get the best expression at 0.6% lactose and around almost 1% glycerol."

The next step:
James Hartley, director of the protein expression laboratory at the National Cancer Institute, has expressed two dozen different proteins using auto-induction. He says he's working to design an instrument that can auto-induce temperature-dependent protein expression.

The numbers:

Lactose
concentration
Optical density/culture growth
(light absorption at 600 nm wavelength)
0.05% 4.2
0.02% 4.9
0.01% 5.5
0.005% 5.8