Biomedical subjects

S E Badger

Publications and source records attributed to S E Badger.

4 recordsLinked to original sources

PubMed2000

Suspended bed chromatography, a new approach in downstream processing.

A new technique in downstream processing, suspended bed chromatography has been developed. This hybrid technique exploiting the benefits of batch adsorption and the process advantages of an enclosed column system can be carried out using established contactors and adsorbents. A 44 cm I.D. IsoPak column and the anion-exchange cellulose Express-Ion Exchanger Q were used in the purification of ovalbumin from hen-egg white. After suspension of 16.25 kg Express-Ion Q in 500 l of feedstock containing 5 g protein/l, adsorption was effected by recirculation of the suspension using the IsoPak slurry preparation station. Protein-loaded adsorbent was collected in the IsoPak column unit, where it was washed and protein desorbed using gradient elution at a flow-rate of 300 cm/h. The entire process was complete in under 3 h. With the introduction of pump-packed column systems and the availability of mechanically strong adsorbents suitable for column separations, suspended bed chromatography offers a new approach to downstream processing and provides a less challenging alternative to batch separations.

Adsorption↗

PubMed1998

New approaches to the isolation of DNA by ion-exchange chromatography.

The performance of different anion-exchange media have been compared for the isolation of plasmid DNA and genomic DNA from bacterial cells and human whole blood. Whatman DEAE-Magarose, based on an agarose bead containing a paramagnetic component, has been compared with prepacked gravity-flow columns containing a derivatised silica matrix. In each case the DNA isolation at various scales of operation was similar both in terms of yield and quality. The magnetic susceptibility of DEAE-Magarose is very high, facilitating the use of this separation technique for rapid flexible batch chromatographic processes, a limitation of the prepacked column techniques.

Chromatography, Ion Exchange↗

PubMed1998

Recent developments of magnetic beads for use in nucleic acid purification.

The performance of Magarose, an agarose-based bead containing a paramagnetic component has been evaluated. The anion exchanger DEAE-Magarose is effective at binding DNA from a crude cell lysate. The plasmid pBluescript was isolated from 1.5 ml Escherichia coli JM109 cell culture, following alkaline lysis yielding 8.2 micrograms high-quality DNA. Under similar binding conditions 21 micrograms of salmon sperm DNA bound to the ion exchangers. The affinity medium oligo-dT Magarose was demonstrated to bind 75 mumol of an oligo-dA probe/g of medium by hybridization. Under similar conditions mRNA could be isolated from a preparation of baby hamster cell total RNA. The magnetic susceptibility of Magarose is very high, facilitating the use of this separation technique for rapid batch chromatographic processes.

Animals↗

PubMed1992

Economic considerations important in the scale-up of an ovalbumin separation from hen egg-white on the anion-exchange cellulose DE92.

The scale-up of the separation of hen egg-white proteins has been investigated using Whatman DE92 anion-exchange cellulose. Having developed suitable chromatographic conditions, a maximum binding capacity of 100 mg protein/ml packed DE92 was determined in a 25-ml column. The process was scaled up 1000-fold and the influence of batch and column techniques on the chromatographic step assessed. Data indicate column processes to be more efficient than batch in the adsorptive stage.

Animals↗