A sterile, concentrated (100X) solution intended for use as one component in a complete culture environment for the growth of human mammary epithelial cells. Each 5 ml bottle of MEGS contains all of the growth factors, hormones, and tissue extracts necessary for the culture of mammary epithelial cells and is the correct amount of supplement for a 500 ml bottle of Medium 171.

When a 500 ml bottle of medium is supplemented with MEGS, the final concentrations of the components in the supplemented medium are:

• Bovine pituitary extract (BPE) (0.4% v/v)
• Recombinant human insulin-like growth factor-I (0.01 µg/mL)
• Hydrocortisone (0.5 µg/ml)
• Human epidermal growth factor (3 ng/ml)