Four bag formats — 2D flat, 3D cuboid, wave/rocker, and tank liner — each solves a different problem. Picking the wrong format wastes money, compromises product quality, and can fail GMP audits. This guide maps each format to its correct application.
The four formats at a glance
| Format | Primary use | Volume range | Key feature |
|---|---|---|---|
| 2D Flat (Pillow) Bag | Drug substance freeze-thaw, small-volume liquid storage | 50 mL – 10 L | Uniform ice front for controlled-rate freezing |
| 3D Cuboid Bag | Bulk liquid storage, media hold, harvest collection | 1 L – 1,000 L+ | High volume-to-footprint ratio, stackable |
| Wave/Rocker Bag | Cell culture — seed train, viral vector production | 1 L – 500 L | Low-shear rocking agitation for sensitive cells |
| Tank Liner | Stainless steel vessel protection, buffer/media preparation | 50 L – 10,000 L | Eliminates vessel cleaning validation |
2D Flat Bags — Drug Substance Freeze-Thaw
The 2D flat pillow geometry is the standard for biopharmaceutical drug substance freeze-thaw for one reason: when placed between controlled-rate freezer (CRF) plates, the thin flat profile ensures both surfaces are cooled simultaneously. The ice front advances from both sides and meets in the middle — producing small, uniform ice crystals with minimal cryo-concentration gradients.
Use 2D bags when: freezing purified drug substance (AAV, lentiviral vector, mAb, enzyme), cryopreserving cell therapy products at small scale, storing small volumes of high-value material at −80°C.
Do not use 2D bags for: large-volume bulk liquid storage at 2–8°C or ambient (inefficient footprint), cell culture (no mixing mechanism).
What volume of 2D bag should I use for AAV drug substance?
Match bag volume to fill volume at 50–80% of nominal capacity. For a 50 mL drug substance batch, use a 100 mL 2D bag. Overfilling reduces the surface-to-volume ratio advantage; underfilling wastes bag cost. Standard sizes: 50 mL, 100 mL, 250 mL, 500 mL, 1 L, 2 L.
3D Cuboid Bags — Bulk Storage
3D cuboid bags (also called pillow bags with gussets, or biocontainer bags) maximise volume per footprint. They are designed for ambient or 2–8°C liquid storage — not for freeze-thaw, where their thick geometry creates heterogeneous ice formation. Use them for media hold, buffer storage, harvest collection, and in-process hold at scale.
Use 3D bags when: storing bulk media or buffers, in-process hold of cell culture harvest, bulk drug substance storage at 2–8°C before fill-finish.
Can I freeze a 3D cuboid bag at −80°C?
Not recommended for drug substance. Freezing creates heterogeneous ice crystal formation in thick-geometry containers — causing cryo-concentration stress and aggregation of sensitive biologics. For −80°C storage, always use 2D flat bags with controlled-rate freezing.
Wave / Rocker Bags — Cell Culture
Wave bioreactor bags are culture vessels that sit on a rocking platform — the rocking motion creates a wave that provides oxygen transfer and mixing without mechanical impellers. This low-shear environment makes wave bags ideal for sensitive cells: HEK293T for AAV production, T cells for CAR-T manufacturing, MSCs for cell therapy seed trains, and insect cells for baculovirus/VLP production.
Available sizes at SeamlessBio: 10 L, 20 L, 50 L
Use wave bags when: scaling AAV or lentiviral vector production beyond static culture, seed train expansion for bioreactor inoculation, T cell or MSC expansion at clinical scale, any culture requiring low-shear suspension conditions.
| Volume | Working volume | Typical application |
|---|---|---|
| 10 L wave bag | 2–5 L | HEK293T AAV seed train, T cell expansion pilot scale |
| 20 L wave bag | 5–12 L | Clinical-scale T cell / MSC expansion, AAV production scale-up |
| 50 L wave bag | 15–30 L | Commercial CAR-T manufacturing, large-scale AAV production |
Tank Liners — Stainless Steel Vessel Protection
Tank liners are single-use inner bags inserted into stainless steel or plastic vessels — eliminating the need to clean and validate the vessel between uses. The liner is the product contact surface; the vessel provides structural support. This is the format used for buffer preparation tanks, media preparation vessels, and large-volume liquid storage at commercial GMP scale.
Use tank liners when: replacing repeated cleaning validation cycles for stainless steel buffer/media prep tanks, managing large-volume (100 L – 10,000 L) liquid logistics, transitioning legacy stainless facilities to hybrid single-use processes.
Universal specifications to require for all formats
- Film material: USP Class VI certified multilayer polyethylene — biocompatibility confirmed
- Sterilisation: gamma-irradiated, 25–45 kGy, sterility certificate per lot
- Extractables & leachables: full E&L data package available — required for IND CMC and BLA submissions
- Integrity testing: 100% per-bag integrity test — pressure or vacuum decay — certificate included
- Port configuration: match to your process — sterile connectors (AseptiQuik, Kleenpak), luer, or TC clamp
- Temperature rating: confirmed for your storage/use temperature range (−196°C cryogenic to +121°C autoclave — not all films cover the full range)
Single-Use Bioprocessing Bags — All Formats, EU Stock
SeamlessBio supplies 2D bags, 3D bags, wave bioreactor bags (10/20/50 L) and tank liners — USP Class VI, gamma sterilised, E&L data on request.
English 
Deutsch