Abstract: A method for continuously preparing a medium formulation mixes a diluent with a plurality of chemically incompatible concentrate solutions in such a manner that none of the ingredients of the concentrate solutions chemically react in an adverse manner. The method utilizes a static mixing chamber to add the concentrate solutions to the diluent stream sufficiently in advance of one another so that adverse chemical reactions do not occur. The method also adjusts a pH level of the diluent prior to adding any of the concentrate solutions to the diluent.

Abstract: The present invention relates to a method of subgrouping media formulations into stable, compatible components that can then be solubilized at high concentrations (10.times. to 100.times.). Concentrated solutions of the ingredient containing subgroups can be used to prepare media formulations. Concentrated culture media formulations (2-10.times.) or 1.times. cell culture media can be prepared according to the present invention by mixing a sufficient amount of the concentrated subgroup solutions with a sufficient amount of a diluent (water, buffer, etc.).The present invention further relates to stabilization of glutamine by complexing or mixing glutamine with divalent metal cations in solution.