The enabling value of monoliths was strongly in evidence at the 4th International Monolith Symposium, held 29 May – 2 June in the Adriatic resort city of Portoroz, Slovenia. Forty-seven oral presentations and 34 posters highlighted important advances in vaccines, gene therapy, phage therapy for infectious disease, and monoclonal antibodies, as well as continuing advances in the performance of monoliths themselves. As these fields advance in parallel, it becomes increasingly apparent that monoliths offer industrial capabilities substantially beyond…
Downstream Processing
How to Choose an Industrial Cation Exchanger for IgG Purification
Cation-exchange chromatography is the third most used industrial method for antibody purification after anion-exchange and protein A affinity chromatography. It is most commonly used as an intermediate step but continues to attract attention as a capture method. This offers obvious cost and cleaning advantages over protein A but also imposes some sacrifices, all of which are discussed in a number of recent articles (1,2,3,4,5). Whichever application may be intended, end users seek a common set of performance characteristics.…
Rapid and Scalable Microplate Development of a Two-Step Purification Process
High-throughput screening and process development methods are becoming more widely used in the biopharmaceutical industry. Recent development of high-expression (high–target-titer) recombinant culture methods has enhanced the need to also develop more effective separation products, methods, and processes (1). Part of the solution would be chromatographic resins offering higher capacities and flow rates. However, developing an optimized purification process that involves several chromatographic steps can consume significant time and samples. In addition, a purification process developed…
Improving IEX Throughput and Performance with Differentiated Chromatography Sorbents
Optimized upstream processing and high-productivity cell culture increase not only target protein titers, but also impurity and contaminant concentrations to be removed from large volumes of feedstock. Simultaneously, biopharmaceutical drug production is increasingly driven by manufacturing cost reduction. These facts together increase the pressure on downstream processing and create an urgent need for more productive and streamlined chromatography operations. Key parameters to consider for enhanced process economics in chromatography are higher protein binding capacities at high flow rates…
How Pore and Fibrous Interstice Structure Influence Filter Performance
When bioprocess liquids bearing suspended particles are filtered, retained particles can block and clog membrane filter pores. The pore size rating of a filter should be selected to retain objectionable particles by sieving, and the aptitude of its polymeric composition for adsorptive sequestration of those particulates also needs to be known. The quantity and nature of retained particles require accommodation if filtrative removal is to be considered successful. Too extensive a particle load will prematurely block a filter’s…
How Pore and Fibrous Interstice Structure Influence Filter Performance
A common objective in pharmaceutical processing is the removal of solids from fluid suspensions through filtration. The usual purpose is the removal of the solid particles to a specified extent, within a given time interval, at the largest possible throughput. Attainment of those goals is managed by proper selection of filtration conditions: principally an adequate effective filtration area (EFA) as defined by filter porosity and a proper rate of flow as regulated by applied differential pressure (ΔP) over…
Single-Use Connections Enable Advancements in Aseptic Processing
Today’s market demand for new drugs — combined with the difficult economic environment — is challenging bioprocessors to review their manufacturing systems and seek ways to make them more flexible, reliable, and cost effective. Increasingly, biomanufacturers are turning to single-use aseptic processing systems to meet or beat aggressive product-introduction timeframes while controlling costs. Innovative new single-use technologies continue to be introduced, giving pharmaceutical companies greater flexibility for replacing traditional stainless tubing, equipment, and even entire process suites with…
Minibodies and Multimodal Chromatography Methods
Small, genetically engineered immunological constructs are being developed industry-wide for a growing range of in vivo applications. Examples include Fab, F(ab’)2, single-chain (sc) Fv, bis-scFV, diabodies, minibodies, and single-domain antibodies (1). Their small size potentially gives them access to tissues that are poorly accessible by intact antibodies; rapid clearance from blood and nontargeted tissues; lower immunogenic response; and eye-drop, inhalant, or oral administration. We report here on purification of an affinity-matured, humanized, antiprostate stem-cell antigen (PSCA) minibody for…
Novel Affinity Ligands Provide for Highly Selective Primary Capture
Downstream processing of biopharmaceuticals is costly and time-consuming, often involving multiple steps with significant time and energy expended on maximizing product quality and yield. Affinity chromatography is one of the simplest and most effective methods for purifying protein and peptide therapeutics, offering reduced process steps and therefore higher yields than nonaffinity methods can provide. Protein A is widely used for affinity purification of monoclonal antibodies (MAbs), Fc fragments, and Fc fusion proteins. But it is a challenge to…
Using In-Line Disposable Pressure Sensors to Evaluate Depth Filter Performance
Development of a recovery process for a fed-batch mammalian cell culture product involves several objectives: process scalability, robustness, maximizing product yield, elimination of subsequent purification steps, and low cost of goods. In an effort to achieve those objectives, we developed a three-stage primary recovery process to remove biomass and clarify the feed stream for downstream column chromatography (Figure 1). The initial stage involves removal of whole cells and larger cellular debris using a continuous disc-stack centrifuge. Depth filtration…