This nutrient-rich microbial broth contains peptides, amino acids, water soluble vitamins and glucose in a low-salt formulation.
It was developed by Douglas Hanahan in 1983 and is an adjusted version of the commonly used LB medium (lysogeny broth).
Growth of E. coli in SOB or SOC medium results in higher transformation efficiencies of plasmids.
Super Optimal broth with Catabolite repression (SOC) is SOB with glucose added to the culture medium as preferred carbon and energy source (i.e., rapidly metabolizable).
The components of SOC medium should not be autoclaved together because at elevated temperature glucose can react with the tryptic peptides (see Maillard reaction), compromising the quality of the preparation.