While cattle-free quarter-pounders or chicken-free nuggets may sound like science fiction, Jason Matheny, lead author of a paper on in vitro meat production in a June 2006 issue of the scientific journal Tissue Engineering, says it's closer than you think. In fact, the University of Maryland graduate student says researchers in the Netherlands and the U.S. expect to perfect a scalable process to produce cost-effective, in vitro (lab-grown), processed meats within five years.

Matheny says the technology isn't new. Medical researchers have long been able to grow muscle tissue in the lab. Factory-grown meat just adapts this technology to industrial-scale meat production. Matheny says it's a logical extension of technology-driven agriculture.

Douglas McFarland, a South Dakota State University animal science professor and co-author, says cattlemen needn't worry about competition from in vitro meat anytime soon.

“I don't imagine I'll be buying a slab of tissue-engineered meat in the supermarket in my lifetime,” McFarland says. “It will remain too expensive, and I don't know if enough money is going to be put into it (research) to make it a reality.”

McFarland believes in vitro technology will first be used for specialty applications, such as supplying astronauts with meat on long space flights.

How it's done

The first step to growing muscle tissue in the lab is to harvest satellite cells — precursors to muscle cells — from a cow using a biopsy. The cells are then put into a vat of “nutritious soup,” Matheny says.

“Over a period of days, the cells divide into millions of daughter cells, just like the original. These are poured onto a sheet with thin grooves in it, which is placed in a bioreactor to grow.”

Muscle cells need to be stretched to grow and develop properly. If not, they have a texture closer to cooked oatmeal than meat. The simplest way to simulate exercise is by flexing the sheets the cells are grown on. Just flexing the sheets by 10% every few minutes is enough to cause the cells to align and fuse into myofibers. Eventually, over a couple of weeks, you have a thin layer of muscle tissue.

Current technology only allows the growth of very thin layers of tissue, which would be suitable for grinding into such traditionally processed meats as hamburger, sausage, chicken nuggets or fish sticks. While current technology could produce a product with an identical flavor and texture to existing processed meats, it's nowhere close to being able to produce a steak. To grow large, three-dimensional pieces of tissue, it's necessary to grow blood vessels to supply nutrients to interior cells.