The process of making cultured meat (also known as clean meat) is similar to making livestock meat, except the cells grow outside the animal’s body.
The first step is to take some cells from the muscle of an animal, such as a cow if we’re making beef, which is done with a small biopsy under anaesthesia.
Myosatellite cells in the proliferation stage. If you were to look at this same plate two days later, it would be completely covered with cells.
Myosatellite cells in the proliferation stage. If you were to look at this same plate two days later, it would be completely covered with cells.
The cells that are taken are called “myosatellite” cells, which are the stem cells of muscles. The function of these stem cells within the animal is to create new muscle tissue when the muscle is injured. It is this inherent talent of the stem cells that is utilised in making cultured meat.
The cells are placed in a medium containing nutrients and naturally-occurring growth factors, and allowed to proliferate just as they would inside an animal.
They proliferate until we get trillions of cells from a small sample. This growth takes place in a bioreactor, which looks similar to the bioreactors that beer and yoghurt are fermented in.
When we want the cells to differentiate into muscle cells, we simply stop feeding them growth factors, and they differentiate on their own. The muscle cells naturally merge to form “myotubes” (a primitive muscle fibre that is no longer than 0.3mm long).
The myotubes are then placed in a gel that is 99% water, which helps the cells form the shape of muscle fibres. The muscle cells’ innate tendency to contract causes them to start putting on bulk, growing into a small strand of muscle tissue.
From one sample from a cow, we can produce 800 million strands of muscle tissue (enough to make 80,000 quarter pounders).
Thousands of individual muscle fibres combine to form a humble hamburger.
Thousands of individual muscle fibres combine to form a humble hamburger.
When all these strands are layered together, we get what we started with – meat.
The meat can then be processed using standard food technologies, for example by putting them through a meat grinder to make ground beef.
We are often asked whether the process involves genetic modification, and the answer is “no”. Genetic modification is unnecessary for the process. The cells are doing what they would normally do inside the animal, so they do not need to be re-programmed in any way.
