Separate Empty and Full AAV Capsids with MCSGP — Gene Therapy Manufacturing.

Setting: AAV2 purification from HEK293 cell lysate via anion exchange chromatography. Starting material with a challenging empty/full capsid ratio.

Batch AEX starting point:

• Full capsid content: ~30% (ddPCR) / ~27% (cryo-TEM)
• Product loss in side-fractions: significant — full capsids recovered at low yield

MCSGP result (6 cycles, same AEX conditions):

• Full capsid content: 68% (ddPCR) / 61% (cryo-TEM) — more than doubling full capsid purity
• Full capsid recovery: substantially higher than batch — yield-purity trade-off overcome
• Online UV260/280 ratio monitoring: successfully identified the empty/full transition zone in real time; confirmed by offline multi-angle light scattering (MALS) and cryo-TEM

Key finding: MCSGP process development starts from your validated batch AEX method — resin, buffers, and gradient conditions are preserved. The online UV260/280 ratio provides a practical, reagent-free PAT signal suitable for AutoPeak® integration. Both analytical techniques (ddPCR and cryo-TEM) confirmed the enrichment — validating the UV ratio as an accessible process monitoring tool for full/empty capsid content.

Müller, J. et al. Biotechnol. Bioeng. (2025). PubMed: 40468522

Setting: AAV2 purification via anion exchange chromatography, Purity specification (Pspec) = 70.0% full capsids.

Batch AEX baseline:

• Yield: ~10–11% full capsids at 70% purity
• Productivity: 3.85×10¹³ VP/(L_resin·h) with 20 CV gradient
• Shallow gradients (30 CV) improve yield slightly (to 11.3%) but dramatically reduce productivity — a hard trade-off

MCSGP result (same AEX resin, same Pspec):

• Yield: 57.8% — approximately 5× higher than batch
• Productivity: 8.65×10¹³ VP/(L_resin·h) — approximately 2.5× higher than the productivity-optimized batch case
• Process mass intensity (PMI): reduced to 1/3 of batch — 3-fold reduction in buffer consumption
• Both high yield and high productivity achieved simultaneously — the trade-off eliminated

Key finding: MCSGP is the only technique that simultaneously improves yield, productivity, and sustainability metrics for the AAV empty/full separation. The study validated MCSGP performance through model-based process design, substantially reducing experimental effort for method transfer.

J. Chromatogr. A (2025). DOI: 10.1016/j.chroma.2025.465001

For AAV programs using commercial affinity resins (POROS CaptureSelect AAVX, AAV8, AAV9; Capto AVB; AVIPure®), CaptureSMB extends twin-column periodic countercurrent chromatography to the capture step — the same principle that delivers 2.5× Protein A productivity for mAbs.

In CaptureSMB mode, two affinity columns operate in a coordinated interconnected and parallel cycle. The lead column loads beyond its single-pass breakthrough point; any breakthrough is captured on the second column in series. This overcomes a key challenge of AAV affinity capture: low dynamic binding capacity relative to the large capsid size (~25 nm) limits resin utilization in conventional batch loading.

Potential benefits for AAV affinity capture:

• Higher resin utilization — load beyond the breakthrough point without product loss
• Higher productivity per column volume — relevant given the high cost of specialty AAV affinity resins
• Reduced buffer consumption — fewer equilibration cycles per gram captured
• Smaller column footprint — important in scale-limited GMP environments

CaptureSMB for AAV affinity capture is in active development. Contact our application specialists for a feasibility assessment. The CUBE supports both CaptureSMB and MCSGP, making it the ideal platform for developing and comparing both steps on the same instrument.

Yes — MCSGP applies to any serotype where AEX gradient chromatography achieves at least partial empty/full resolution. Published proof-of-concept is on AAV2 (Müller et al. 2025; Grob et al. 2025). The Contichrom CUBE enables rapid method adaptation to AAV5, AAV8, AAV9, and engineered capsid variants.

No. MCSGP uses the same anion exchange resin, buffers, and gradient conditions as your existing validated batch AEX method. Transitioning from batch to MCSGP requires only translation of the batch gradient into an MCSGP operating strategy — ChromaCon’s application specialists support this as part of the standard feasibility assessment.

AutoPeak® uses the real-time UV260/280 absorbance ratio as the primary PAT signal. Empty capsids have a lower UV260/280 ratio than full capsids. As elution transitions through the mixed zone, AutoPeak® detects the shift online and automatically defines recycling window boundaries — confirmed against cryo-TEM and multi-angle light scattering (Müller et al. 2025).

At a 70% full-capsid purity specification, MCSGP achieved ~58% yield versus ~10–11% for batch — a ~5× improvement (Grob et al. 2025). Starting from 30% full capsids, Müller et al. (2025) achieved 68% full-capsid content. Expected outcomes for your program depend on starting material and target purity; ChromaCon’s feasibility assessment provides molecule-specific projections.

In Müller et al. (2025), 6 MCSGP cycles achieved the reported enrichment. Cycle number and run time depend on feed volume, column size, gradient length, and target purity. Method development on the Contichrom CUBE typically requires one to a few days. Manufacturing-scale batch duration is modeled as part of a feasibility study.

FDA guidance and ICH Q6B call for characterization of capsid content as a critical quality attribute. Many programs target ≥90% full capsids in the final drug substance. MCSGP with AutoPeak® enables reproducible full-capsid enrichment from variable upstream feeds — directly supporting lot-to-lot consistency and regulatory compliance.

Yes. Both the CUBE and TWIN LPLC support MCSGP and CaptureSMB on the same hardware, switchable via ChromIQ® software. A single instrument covers affinity capture development (CaptureSMB) and polishing development (MCSGP) — enabling a fully integrated continuous two-step purification strategy.

The Contichrom TWIN LPLC covers clinical through commercial scale (column volumes from 100 mL to 2 L). Scale-up from CUBE to TWIN LPLC is linear — column chemistry, gradient conditions, and AutoPeak® control logic are preserved. cGMP design, 21 CFR Part 11 compliance, and IQ/OQ/PQ documentation packages are available.