Continuous bioprocessing is transforming how biologics are discovered, developed, and manufactured by replacing large, stop start unit operations with small, steady flows of material. It supports higher productivity, better product quality, and smaller facility footprints while enabling data rich decision making. In this article, we explore the Top 10 Continuous Bioprocessing Approaches in BioTech that organizations can adopt to scale efficiently and compliantly. You will learn how upstream and downstream steps can be linked, controlled, and released with real time analytics. The goal is to give basic and advanced knowledge seekers a structured, practical guide that you can apply in development and manufacturing.
#1 Perfusion bioreactors for steady state production
Perfusion bioreactors maintain cells in a steady state by continuously feeding fresh media and removing product containing harvest while retaining cells in the vessel. This approach decouples cell growth from product removal, enabling very high cell densities, stable metabolite profiles, and consistent critical quality attributes. Design choices include internal spin filters, external alternating tangential flow modules, and tangential flow filters, with selection driven by shear sensitivity and fouling risk. Key controls track specific perfusion rate, viable cell volume, and oxygen transfer. Perfusion reduces bioreactor size for a given output, lowers facility footprint, and provides a robust platform for linking directly to continuous capture chromatography.
#2 Cell retention technologies ATF and TFF
Cell retention is central to continuous upstream, keeping biomass in the reactor while allowing clarified harvest to exit. Alternating tangential flow systems use a diaphragm pump to oscillate flow across hollow fibers, minimizing cake buildup and shear. Classic tangential flow filtration uses constant crossflow and pressure control to achieve stable permeate, with careful management of transmembrane pressure and flux. Acoustic settlers and inclined settlers can further clarify or replace filters for delicate cells. Robust operation depends on smart fouling management, periodic backflushing, and inline turbidity monitoring, which sustain stable harvest quality and enable long, productive campaigns with predictable downtime windows.
#3 Intensified seed trains and N perfusion
Intensified seed trains accelerate time to production scale by raising inoculum density and shortening expansion steps. Strategies include perfusion based seed bioreactors that generate large viable cell volumes, and N perfusion, where intensified media exchange precedes the production phase. Higher starting cell densities reduce time to steady state, improve volumetric productivity, and create a more uniform metabolic baseline. Disposable bioreactors simplify logistics and reduce cleaning validation. Digital scheduling and capacity modeling help right size shake flasks, wave bags, and small reactors. Together, these practices compress timelines, stabilize upstream variability, and improve readiness for seamless connection to downstream continuous capture operations.
#4 Multi column continuous capture chromatography
Multi column continuous capture chromatography increases resin utilization and productivity by cycling columns between load, wash, and elute in a staggered pattern. Periodic counter current systems use two or three columns to capture breakthrough from one column onto the next, enabling operation at higher loadings without yield loss. Simulated moving bed variants provide additional efficiency for certain separations. Automated valve skids control flow paths, while mass balance and UV signals maintain dynamic binding capacity targets. Benefits include smaller skids, reduced buffer consumption, and tighter residence time distribution. When linked to perfusion harvest, continuous capture delivers steady pools that simplify viral inactivation and downstream polishing design.
#5 Continuous viral inactivation reactors
Continuous viral inactivation replaces large hold tanks with precisely controlled residence time reactors that mix low pH buffer with the capture pool and maintain defined exposure. Approaches include coiled flow inverters, oscillatory baffled reactors, or staged tubular reactors with static mixers that deliver narrow residence time distributions. Online pH, conductivity, and temperature monitoring ensures conditions remain within validated design space. Residence time verification uses tracer studies and PAT signals to demonstrate compliance. The result is a safer, smaller operation with faster recovery to normal after deviations, improved operator ergonomics, and straightforward integration between multi column capture and flow through polishing steps.
#6 Continuous polishing with membranes and columns
Continuous polishing removes residual impurities such as host cell proteins, DNA, and aggregates using flow through or cycling operations. Membrane adsorbers provide high throughput for anion exchange flow through, while mixed mode or hydrophobic interaction resins can operate in connected column trains. Switching valves and online UV or light scattering signals manage column cycling and breakthrough. Careful control of conductivity and pH using inline dilution gives consistent selectivity. This stage takes advantage of steady upstream pools, leading to smaller media volumes and lower buffer usage. Integrated polishing creates predictable product pools for ultrafiltration and supports real time release strategies with consistent impurity clearance.
#7 Single pass ultrafiltration and diafiltration
Single pass ultrafiltration and diafiltration concentrate and exchange buffers without recirculation, enabling continuous flow from polishing into final formulation. By staging multiple cassettes, operators achieve targeted concentration and diafiltration volumes with low shear and tight residence time control. Critical variables include transmembrane pressure, feed flux, and stage cut, which are tuned using online flow and pressure sensors. Automated balance tanks or accumulator bags smooth small disturbances. Benefits include smaller hold volumes, reduced product exposure time, and simpler cleanability. When combined with inline dilution and conductivity control, single pass operations deliver consistent product for sterile filtration and filling, improving end to end process robustness.
#8 Inline buffer dilution and conditioning
Inline buffer dilution and conditioning shrink utility footprints by generating process buffers from a few concentrated stocks at point of use. Skids precisely blend water for injection with acid, base, and salt solutions using mass flow controllers and feedback from inline pH and conductivity probes. Recipes are version controlled and linked to chromatography setpoints, enabling automated transitions between steps. This reduces tank farm size, improves operator safety, and eliminates manual preparation errors. In continuous trains, buffer management aligns delivery with column cycling and residence time requirements, ensuring steady flow and composition. The result is lower cost, faster changeover, and repeatable performance across scales and sites.
#9 Real time release, PAT, and advanced control
Real time release relies on process analytical technology, multivariate models, and advanced control strategies that maintain state of control without large end product tests. Spectroscopic tools such as Raman and near infrared track nutrients, metabolites, and titer in upstream, while UV, conductivity, and light scattering monitor downstream. Multivariate statistical process control and model predictive control adjust feeds, pool cuts, and buffer ratios in response to variability. Data integrity is ensured through validated data historians and automated exception handling. Together, these tools shorten feedback cycles, improve comparability across campaigns, and enable confident release decisions aligned with modern regulatory expectations.
#10 End to end integration and facility design
End to end continuous integration requires deliberate facility and quality design that treats the process as a connected system. Modular skids, single use flow paths, and ballroom layouts simplify reconfiguration and scale out while maintaining closed operations. Material flow and line clearance are planned with dynamic scheduling that respects residence time and column cycling. A holistic control strategy links critical process parameters to critical quality attributes across units, supported by deviation management and robust change control. Technology transfer packages include digital twins, recipes, and mass balance models, ensuring predictable startup and long term operability across manufacturing sites.