LOS ANGELES, June 21 (Xinhua) -- U.S. regulators have approved the sales of cell-cultured chicken to customers in a landmark decision, the two startups that received the first approvals said on Wednesday.

The U.S. Department of Agriculture (USDA) issued approval to two startups -- GOOD Meat and UPSIDE Foods. Both companies had already received the go-ahead months earlier from the U.S. Food and Drug Administration (FDA), which said each company's lab-grown chicken is safe for human consumption.

"This landmark clearance means the firm's chicken, which is made directly from animal cells, can now be sold to American consumers," GOOD Meat said in a statement.

In order to be cleared to produce and sell cultivated meat, UPSIDE Foods' team of food scientists, molecular biologists, and technical engineers passed three extensive regulatory steps: "No Questions" Letter from the FDA, USDA Label Approval, and USDA Grant of Inspection, said the company in a statement.

Cultured meat, also known as cultivated, cell-based or lab-grown protein, is made by putting stem cells from an animal in a vessel called a cultivator, and feed them the right blend of nutrients to multiply and grow.

After two to three weeks, the meat is harvested, formulated, and ready to enjoy, according to introduction of UPSIDE Foods.