Our experiences with the expression of recombinant proteins have shown that the level of expression is very much dependent on the medium used. Some proteins are expressed well in one medium, but are not expressed in the same host strain in another medium. Or protein may be expressed in one medium while another protein is not expressed in the same medium. This demonstrates why for each recombinant protein a medium screen becomes a crucial part of the optimization process. To facilitate the researcher’s efforts to develop the best systems for their proteins, we have developed a Media Optimization Kit™.

This kit is composed of six media formulations (including four that are unique and proprietary) which we have found over the years to be the most reliable for the increased production of recombinant proteins in Escherichia coli. The kit is used to quickly and easily identify the most suitable medium for the expression of a particular recombinant protein. Included are suggested approaches for improving the production of recombinant proteins, thus passing along the knowledge our staff scientists have acquired while working to produce a wide variety of proteins.

Superior Broth™, Superior Prime Broth™, and new Superior Prime-olate™, are proprietary media formulations for improved expression of recombinant proteins in E. coli. The formulations are complex, supplying a nitrogen source, vitamins, and moderate glucose levels. The media are buffered at pH 7.2 ± 0.2 to prevent acidification of the medium during metabolism of the glucose. Expression of recombinant proteins should be induced at cell densities twice that of LB Broth. Cell yields are typically 3 to 4 times that of LB Broth. Superior Broth™ shows the highest plasmid copy numbers among this family of media. This medium is an excellent choice for large-scale plasmid preparations. Biomass yields will depend on the process and the strain employed.

Tan to light brown, free flowing powder.

Amber, clear, complete at 35g/L (with slight heat)

~7.0

1. Dissolve 35g in 1L deionized water. 2. Dispense at desired volume into appropriate bottles or flasks. 3. Autoclave at 121°C for 15-20 min, depending on the volume per container. Allow to cool. 4. Add sterile antibiotics as needed.

Store powdered media at RT. Stable for 12 months after receipt. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4°C and used within a short period of time.

P9102-40 Media Optimization Kit™ P9102-40A Turbo Broth™ P9102-40B Superior Broth™ P9102-40C Power Broth™ P9102-40D Hyper Broth™ P9102-40E M9Y (Glucose) Broth™ P9102-40F Glucose-Nutrient Mix P9102-40G LB Broth (Miller)