I am working with mouse microglial cells and the culture protocol calls for supplementing culture medium with 10% FBS and 5% horse serum (both heat-inactivated). While the FBS is abundantly available, horse serum is not available in any of the local distributors' stocks. I am running out, and I don't know what to do. Is there any alternative to horse serum that would contain comparable amounts of proteins and minerals? If not, are there any suggestions as to how to continue culturing these cells?
Thank you! :)