Development of a high-throughput scale-down model in Ambr® 250 HT for plasmid DNA fermentation processes.

Recent advances in messenger ribonucleic acid (mRNA) vaccines and gene therapy vectors have increased the need for rapid plasmid DNA (pDNA) screening and production within the biopharmaceutical industry. High-throughput (HT) fermentor systems, such as the Ambr® 250 HT, can significantly accelerate process development timelines of pDNA upstream processes compared to traditional bench-scale glass fermentors or small-scale steam-in-place (SIP) fermentors. However, such scale-down models must be qualified to ensure that they are representative of the larger scale process similar to traditional small-scale models.

Voltage dependent closure of PorB class II porin from Neisseria meningitidis investigated using impedance spectroscopy in a tethered bilayer lipid membrane interface.

Electrochemical impedance spectroscopy (EIS) was used to characterize voltage-dependent closure of PorB class II (PorBII) porin from Neisseria meningitidis incorporated in a tethered bilayer lipid membrane (tBLM). The tBLM's lower leaflet was fabricated by depositing a self assembled monolayer (SAM) of 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) on a gold electrode, and the upper leaflet was formed by depositing1,2-dioleoyl-sn-glycero-3-phoshocholine (DOPC) liposomes. At 0mV bias DC potential, incorporation of PorBII decreased the membrane resistance (R(m)) from 2.

Functional characterization of PorB class II porin from Neisseria meningitidis using a tethered bilayer lipid membrane.

PorB class II from Neisseria meningitidis is a pore-forming, outer-membrane protein that can translocate to the host-cell membrane during Neisserial infections. This report describes development of tethered bilayer lipid membrane (tBLM) system to measure PorB conductance properties. The tBLM was fabricated by depositing a self-assembled monolayer of 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) tethering lipid on a gold electrode and then using 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes to deposit the upper tBLM leaflet.

Fabrication of highly insulating tethered bilayer lipid membrane using yeast cell membrane fractions for measuring ion channel activity.

A tethered bilayer lipid membrane (tBLM) was fabricated on a gold electrode using 1,2-dipalmitoyl-sn-glycero-phosphothioethanol as a tethering lipid and the membrane fractions of Saccharomyces pombe yeast cells to deposit the upper leaflet. The membrane fractions were characterized using transmission electron microscopy and dynamic light scattering and found to be similar in size to small unilamellar vesicles of synthetic lipids. The dynamics of membrane-fraction deposition and rupture on the tethering-lipid layer were measured using quartz crystal microgravimetry.