RECOMBINANT PROTEINS
CaptureSMB® capture and MCSGP polishing on the Contichrom® platform — MCSGP demonstrated in collaboration with Bristol Myers Squibb on a PEGylated protein at 98% target purity: +8.2 pp Yield (73.1→79.1%) | +17.8% Productivity | −15% PMI | lowest COG of all five scenarios modelled. With dual-slope MCSGP: yield further increases to +20–23 pp vs. batch maximum. CaptureSMB® separately validated at 100× scale-up by BMS for Protein A capture.
Sources: Kim et al., J. Chromatogr. A (2022) — BMS industrial-scale COG study; Kim et al., J. Chromatogr. A(2023) — dual-slope MCSGP; CaptureSMB®, production-scale BMS validation: Angelo et al., BioProcess International 2018
Batch bind-and-elute chromatography leaves resin capacity systematically underutilized. A column is loaded to 60-80% of dynamic binding capacity to avoid product breakthrough — meaning 20-40% of expensive affinity resin sits idle in every cycle.
For high-cost resins — Protein L for F(ab’)₂ fragments, Protein A for Fc-fusion proteins, or custom affinity supports for novel scaffolds — this underutilization directly inflates cost of goods. Add the large buffer volumes required for batch cycling and the long processing times for high-titer feeds, and affinity capture becomes a significant manufacturing bottleneck.
For manufacturers targeting continuous downstream processing or integration with perfusion bioreactors, batch capture also introduces the largest process time discontinuity in the train.
CaptureSMB® uses a twin-column countercurrent loading strategy to maximize affinity resin utilization. While the first column reaches full saturation, breakthrough is captured on the second column — ensuring near-complete loading of both columns before any elution occurs. Resin utilization consistently reaches ≥95% versus 60-80% for batch loading.
AutomAb® dynamic process control monitors UV breakthrough in real-time and triggers column switching automatically, maintaining optimal loading regardless of feed titer variation — enabling robust operation directly coupled to a perfusion bioreactor or continuous clarification train.
CaptureSMB® is compatible with any affinity, IEX, or mixed-mode capture resin — Protein A, Protein L, Protein G, and custom affinity ligands.
Works with any affinity resin. CaptureSMB® has been demonstrated for Protein A (mAb and Fc-fusion capture), Protein L / KappaSelect (F(ab’)₂ and κ-light chain fragment capture), and custom affinity resins. The twin-column principle applies to any bind-and-elute system where maximizing resin utilization and minimizing buffer consumption is valuable.
Load
Resin cost savings (F(ab’)₂ / Protein L)
Productivity
Buffer Consumption
| Parameter | Batch Bind-and-Elute | CaptureSMB® with AutomAb® |
|---|---|---|
| Resin Utilization | 60% (breakthrough avoidance) | ≥95% — countercurrent loading saturates both columns |
| Resin Cost | Baseline | >30% savings demonstrated for Protein L |
| Product Concentration | Baseline | 2.2× higher in eluate (F(ab’)₂) |
| Buffer Consumption | High (Lower load = large wash/elution volumes per g) | 54% Reduced (Higher load = lower wash/elution volumes per g) |
| Feed Variability Handling | Fixed breakthrough limit; manual adjustment required | AutomAb® dynamically adjusts column switching to real-time UV signal |
| Perfusion Integration | Batch holds required between harvest and capture | Direct coupling |
| Process Control | Manual or timer-based column switching | Automated (AutomAb® UV-based PAT) |
| Resin / Buffer Compatibility | Any affinity, IEX, or mixed-mode | Same — no change required |
Recombinant proteins rarely elute as a single, pure species. Charge variants, aggregates, PEGylation isoforms, and process-related impurities co-elute with the target — and conventional batch polishing cannot resolve them without a costly trade-off.
A tight center-cut achieves target purity but discards large fractions of expensive product. Widening the cut improves yield but fails purity specifications. Recovering side-fractions through re-chromatography adds time, buffer, and complexity.
For high-value proteins — including PEGylated bioconjugates, Fc-fusion proteins, cytokines, recombinant enzymes, and growth factors — this inefficiency directly inflates cost of goods and delays manufacturing throughput.
MCSGP (Multi-column Countercurrent Solvent Gradient Purification) eliminates the purity–yield trade-off. Two identical columns continuously recycle impure side-fractions back into the purification cycle — recovering product that batch processes discard as waste. It operates with the same IEX, HIC, mixed-mode, or affinity resins and buffers already used in your polishing step.
AutoPeak® dynamic process control monitors elution profiles in real-time via UV and conductivity, automatically adjusting collection windows to maintain consistent output quality — enabling robust, unattended 24/7 operation.
Same chemistry. Better outcomes. MCSGP is compatible with cation exchange (CEX), anion exchange (AEX), hydrophobic interaction (HIC), and mixed-mode resins at any column size. Your existing resin and buffer conditions are the starting point — no change to your chromatographic chemistry is required.
Yield Increase
PMI / Buffer Reduction
Productivity Gain
Re-chromatography Runs
| Parameter | Batch Polishing | MCSGP with AutoPeak® |
|---|---|---|
| Purity–Yield Trade-off | Inherent — narrow cuts sacrifice yield | Eliminated — high purity AND yield simultaneously |
| Product Yield | 60–80% (typical polishing step) | +8–23% absolute improvement |
| Re-chromatography | Required for off-spec side-fractions | Eliminated — internal countercurrent recycling |
| Buffer Consumption (PMI) | High | −15% demonstrated at industrial scale |
| Productivity | Limited by single-column throughput | Up to +18% improvement |
| Cost of Goods | Baseline | Reduced across all manufacturing scenarios |
| Campaign Flexibility | Fixed batch cadence | Adjustable by tuning cycle number and column diameter |
| Process Control | Manual fraction collection | Automated (AutoPeak® UV-based PAT) |
Fc-fusion proteins are captured via Protein A affinity — the same resin and method as for full-length mAbs. CaptureSMB® continuous loading applies directly, maximizing resin utilization and product concentration for this growing class of therapeutics.
Antibody fragments lacking the Fc region require Protein L, Protein G, Protein A (for Fc-containing fragments), or custom affinity resins. CaptureSMB® has been demonstrated for F(ab’)₂ capture using Protein L (>30% resin savings, 2.2× product concentration vs. batch) and applies to any κ-light-chain-containing fragment.
Many recombinant proteins are captured by custom affinity or mixed-mode resins. CaptureSMB® is compatible with any bind-and-elute system — the performance benefits (≥95% resin utilization, higher product concentration, reduced buffer use) scale to any affinity resin cost and titer.
CaptureSMB’s continuous loading mode couples directly to perfusion bioreactor output — eliminating large intermediate hold tanks, reducing facility footprint, and enabling true end-to-end continuous biomanufacturing from expression to purified drug substance.
PEGylation creates multiple isoforms (mono-, di-, multi-PEGylated) that overlap in conventional IEX or AEX chromatography. MCSGP separates isoforms with simultaneous high purity and yield — demonstrated on both model and industrially relevant molecules with full COG analysis (BMS collaboration).
Cytokines (IL-2, IFN-α, G-CSF, EPO) and growth factors are produced as charge variant mixtures from microbial or mammalian expression. MCSGP IEX polishing recovers the target isoform at high yield while rejecting deamidated, oxidized, or truncated species — without the yield loss of batch center-cutting.
Enzymes produced in microbial or yeast systems carry process-related impurities and isoforms requiring polishing. MCSGP is applicable wherever gradient IEX, HIC, or mixed-mode polishing is already in use — the continuous version operates on the same resin and buffer system with no chemistry change.
Fc-fusion proteins (e.g., etanercept, romiplostim class) require charge variant polishing after Protein A capture. MCSGP continuous IEX or HIC polishing applies directly, removing acidic/basic variants at higher yield than batch center-cutting and enabling tighter CQA specifications if needed.
Protein aggregates and high-molecular-weight species co-eluting with the monomer peak cannot be removed at high yield by batch center-cutting. MCSGP recycles these side-fractions internally, recovering monomer product while meeting tight aggregate specification limits.
Ready to Intensify Your Recombinant Protein Downstream Process?
This application note presents a systematic approach for optimization of MCSGP with regards to the performance parameters Yield, Productivity and Eluent Consumption, and gives recommendations on the priority of the parameters.
This application note provides a simple step-bystep flowchart template to guide the development of batch gradient conditions that result in optimal input data for the MCSGP wizard.
Investigation of gradient slope effects during MCSGP internal recycling provides insights for process optimization of PEGylated protein separations. J. Chromatogr. A
Economic analysis of MCSGP for industrial PEGylated protein separation establishes cost-benefit frameworks for technology adoption.
A model-based approach for MCSGP design applied to PEGylated protein separation improves yield and productivity by 8.2% and 17.8% respectively versus batch processing.
