Amino acids are the constituent sub-units of proteins and represent an essential element of cell culture media. There are 8 essential amino acids in humans (Ileu, Leu, Lys, Meth, Phe, Treo, Trp, Val). As well as other amino acids whose synthesis capacity has been lost during the transition to in vitro such as Gln, Tyr, Cys, Arg and His.

L-arginine is considered one of the most versatile amino acids, as it serves as a precursor to many important molecules in cell physiology. Arginine plays an important role in cell division, wound healing, removal of ammonia from the body, immune function and hormone release. It is a precursor to nitric oxide (NO) synthesis, which makes it important in the regulation of blood pressure. Nitric oxide and polyamines stimulate cell proliferation and have a positive effect on cell cycle progression.