Merck, H0262-10VL, HAT Media Supplement (50×) Hybri-Max™

Sigma-Aldrich Hybri-Max HAT Media Supplement combines hypoxanthine, aminopterin and thymidine for selective cell culture, especially hybridoma workflows following cell fusion. Aminopterin inhibits de novo nucleotide synthesis, while suitable hybridomas use the salvage pathway supported by hypoxanthine and thymidine. The supplement is provided as gamma-irradiated, lyophilized BioXtra material in a package of ten vials. Reconstituting one vial with 10 mL of sterile culture medium produces a 50× stock for preparing 500 mL of final supplemented medium. At working strength, the formulation provides 100 µM hypoxanthine, 0.4 µM aminopterin and 16 µM thymidine. Medium base, cell-culture conditions and the required selection timeline depend on the hybridoma protocol. HAT selection and subsequent HT maintenance perform different functions; the aminopterin-containing HAT supplement is not interchangeable with the aminopterin-free HT supplement during the initial selection phase.