AT110 is CMRL 1066 Medium with L-glutamine. CMRL 1066 is a chemically defined medium formulated for long term cultivation of mouse L cells in the absence of protein supplement. CMRL media are based on the composition of Medium 199. Nucleic acid derivatives, coenzymes omitted in H597 modification were retained in CMRL 1066. CMRL 1066 is a chemically defined medium formulated for long term cultivation of mouse L cells in the absence of protein supplement. Although originally designed for use in serum free conditions, this medium supports growth of a variety of cell lines in the presence of serum.