A bicistronic vector with destabilized mRNA secondary structure yields scalable higher titer expression of human neurturin in E. coli.

Human neurturin (NTN) is a cystine knot growth factor with potential therapeutic use in diseases such as Parkinson's and diabetes. Scalable high titer production of native NTN is particularly challenging because of the cystine knot structure which consists of an embedded ring comprised of at least three disulfide bonds. We sought to pursue enhanced scalable production of NTN in Escherichia coli.

Carbonaceous sorbents for high-temperature interactive liquid chromatography of polyolefins.

The elution behavior of polyethylene (PE) and the three stereoisomers of polypropylene (PP) was studied on porous graphite along with three other carbon-based sorbents, carbon-clad zirconia particles, activated carbon, and exfoliated graphite in a systematic way in this work. Decahydronaphthalene, 1,2,3,4-tetrahydronaphthalene, 1,3,5-trimethylbenzene, tetrachloroethylene, xylene and p-xylene were used as mobile phases. While PE is adsorbed to various extents on all the tested carbonaceous sorbents from the majority of the solvents, PP is fully adsorbed only in selected cases.

Elution behavior of polyethylene and polypropylene standards on carbon sorbents.

The elution behavior of linear polyethylene and isotactic, atactic and syndiotactic polypropylene was tested using three different carbon column packings: porous graphite (Hypercarb), porous zirconium oxide covered with carbon (ZirChrom-CARB), and activated carbon TA 95. Several polar solvents with boiling points above 150°C were selected as mobile phases: 2-ethyl-1-hexanol, n-decanol, cyclohexylacetate, hexylacetate, cyclohexanone, ethylene glycol monobutyl ether and one non-polar solvent, n-decane. Polyethylene standards were completely or partially adsorbed in all tested sorbent/solvent systems.

Twenty-four well plate miniature bioreactor system as a scale-down model for cell culture process development.

Increasing the throughput and efficiency of cell culture process development has become increasingly important to rapidly screen and optimize cell culture media and process parameters. This study describes the application of a miniaturized bioreactor system as a scaled-down model for cell culture process development using a CHO cell line expressing a recombinant protein. The microbioreactor system (M24) provides non-invasive online monitoring and control capability for process parameters such as pH, dissolved oxygen (DO), and temperature at the individual well level.