A method for the isolation of Chinese hamster cell variants with an altered ability to utilise carbohydrates.

Chinese hamster ovary cells (CHO-K1) are able to utilise only a few carbohydrates for growth such as glucose, mannose, fructose and galactose. They do not grow on ribose, lactose, sucrose, glycerol, lactate, pyruvate, citrate, succinate, fumarate or malate nor on glycogenic or ketogenic amino acids. After mutagenesis and selection in glucose free medium supplemented with various, individual, growth substrates, we have isolated single-cell derived clones which are now able to grow on one of the following energy source: ribose, lactose, sucrose or lactate.