Engineering Guide · Vendor-Neutral

Single-Use vs Reusable DO Sensor for Bioreactors: Which to Choose?

Published April 22, 2026 · 10 min read

Scope: this guide is about dissolved oxygen sensors for stirred-tank bioreactors (single-use bag vs reusable stainless steel). It does not cover pulse oximeters for patient monitoring, automotive lambda sensors, wastewater DO probes, or consumer single-use-plastic debates — all of which Google sometimes mixes into this query.

Figure 1: Single-use DO sensors (left) live inside pre-sterilised disposable bags as non-invasive optical patches; reusable DO probes (right) insert through a standard port into a stainless steel vessel and survive hundreds of cleaning cycles.

Quick Verdict

The choice is vessel-driven, not probe-driven. If you're running a single-use bioreactor (SUB) bag, you use the gamma-pre-sterilised optical spot that came with it — there is no realistic alternative. If you're running a reusable stainless steel bioreactor, you use an autoclavable insertable probe like Hamilton VisiFerm or Mettler Toledo InPro 6950i. The real decision happens one step earlier — single-use vessel vs reusable vessel. Sensor selection follows vessel selection automatically.

Key differences at a glance

Single-use DO sensor: gamma-sterilised optical patch glued inside bag wall by the bag vendor; factory-calibrated; one batch lifetime; £30-£80 per bag (bundled).
Reusable DO sensor: insertable probe with Arc or ISM transmitter; autoclave + CIP/SIP; 50-300 batch lifetime; £1,500-£3,500 capital per channel.
Vessel drives the choice: SUB → single-use; reusable SS → reusable probe.
Scale ceiling: single-use limited to ~2,000-6,000 L bag capacity; reusable scales to 25,000 L+.
Multi-product flexibility: single-use eliminates cross-contamination and cleaning validation — decisive for CDMOs.

Side-by-side comparison

Factor	Single-Use DO Sensor	Reusable DO Sensor
Typical form factor	Gamma-sterilised optical spot inside bag wall	Insertable probe (PG13.5, 12 mm, Arc/ISM transmitter)
Sterilisation	Pre-gamma by bag vendor (done)	Autoclave + CIP/SIP cycles on site
Lifetime	One batch (discarded with bag)	50-300 batches with maintenance
Per-channel capital cost	Included in bag price	£1,500-£3,500
Per-batch consumable cost	£30-£80 (inside the bag)	~£0 amortised after capital recovery
Calibration workflow	Factory pre-cal via batch code (one-point)	Pre-run 2-point + re-cal every 20-40 batches
Cross-contamination risk	Near-zero (bag discarded)	Requires cleaning validation per product
Scale ceiling	~2,000 L common, up to 4-6,000 L commercial	25,000 L+ routine
Vendor flexibility	Bag vendor + sensor vendor must be compatible	Standalone; any PG13.5-compatible probe works
Best for	SUBs, CGT, CDMO multi-product, clinical supply	Large-scale mAb, microbial fermentation, high-throughput campaigns

Values reflect typical bioprocess deployment patterns. Vendor datasheets take precedence for specific instrument specs.

Single-use DO sensors explained

Single-use DO sensors for bioreactors are overwhelmingly optical luminescence-quenching spots glued inside the bag wall during bag manufacturing. Sartorius Biostat STR, Thermo Fisher HyPerforma, and Cytiva Xcellerex all ship bags with pre-integrated PreSens SP-PSt3 / PSt6 sensor spots by default. Hamilton's alternative approach is VisiFerm SU, a single-use probe variant that mates with a pre-integrated sterile adapter in the bag.

How they work

The sensor spot is a polymer disc containing a luminescent ruthenium or platinum-porphyrin dye. An LED in the external fiber-optic reader shines through the transparent bag window onto the spot; the dye fluoresces; oxygen molecules collide with the excited dye and shorten its emission lifetime. The reader measures the phase shift of modulated light — insensitive to intensity drift from reader ageing or bag-film fogging — and converts it to percent air saturation or ppm DO. The entire bag arrives pre-gamma-sterilised from the vendor's facility. On site, the user simply clamps the reader to the bag, reads the batch-specific calibration code from the packaging, and starts measuring.

When single-use wins

Single-use DO sensors dominate three scenarios. Single-use bag bioreactors themselves — the sensor is decided the moment you choose the bag vendor; there is no practical alternative. CDMO multi-product campaigns — running Product A on Monday and Product B on Wednesday with zero cleaning validation between batches is uniquely single-use territory. Autologous cell therapy (CAR-T) — each patient gets a dedicated bag, and the lack of shared hardware eliminates cross-patient contamination risk entirely.

Reusable DO sensors explained

Reusable DO sensors for bioreactors are insertable probes designed for stainless steel or glass vessels with a standard PG13.5 port. They fall into two technology camps — optical (luminescence) or polarographic (Clark cell) — and both come from the same major vendors: Hamilton VisiFerm DO Arc, Mettler Toledo InPro 6950i / 6050, Endress+Hauser Memosens COS81D, Broadley-James OxyProbe, and a handful of regional specialists.

How they work

The probe inserts through a PG13.5 threaded port, mechanically sealed with a glands-and-gasket arrangement rated for 121 °C and 4 bar. The probe body survives hundreds of autoclave and CIP/SIP cycles; consumables (membrane and electrolyte for polarographic, or occasionally the dye patch for optical) are replaced every 6-12 months. The transmitter lives in the probe head (Arc, ISM) or externally (legacy amperometric). Output is mA, RS485, HART, or digital — compatible with every major DCS platform.

When reusable wins

Reusable dominates at scale and at throughput. Commercial mAb manufacturing above 5,000 L — single-use bags hit a scale ceiling around 4-6,000 L; commercial blockbusters need 10,000-25,000 L stainless. High-throughput microbial fermentation — running 100+ batches per year per vessel makes the per-batch consumable cost of single-use dominate, while the reusable probe amortises to near-zero. Legacy validated cGMP processes where switching to single-use would trigger a full revalidation campaign — often more expensive than continuing with the existing reusable infrastructure for the product's remaining lifecycle.

Pros and cons

Single-use DO sensor

Advantages

Zero cleaning validation — bag is discarded after one batch
Near-zero cross-contamination risk — no shared hardware
Factory-calibrated — one-point adjustment with batch code, no 2-point workflow
Fast batch turnaround — no CIP/SIP, no probe prep
Ideal for CDMO multi-product and autologous cell therapy

Disadvantages

Per-batch cost accumulates at high batch frequency
Vendor lock-in — sensor is pre-chosen by the bag manufacturer
Scale ceiling at ~4-6,000 L bag capacity
Plastic waste per batch (50-100 kg of bag + internals)
Supply chain dependency on bag + gamma-irradiation providers

Reusable DO sensor

Advantages

Amortised capital — effectively zero per-batch cost at high throughput
Scales from bench 2 L to commercial 25,000 L+
Vendor flexibility — any PG13.5-compatible probe works
Proven cGMP pedigree across 40+ years of deployment
Lower water/chemical waste per batch than single-use plastic

Disadvantages

CIP/SIP cleaning validation required per product
Cross-contamination risk between products on shared hardware
Slower batch turnaround (8-24 h CIP/SIP vs 4-8 h bag change)
Consumables and maintenance labour (especially polarographic membranes)
Higher upfront capital — probes, transmitters, WFI / steam infrastructure

Which should you choose?

The decision is driven almost entirely by vessel type, scale, and whether you need multi-product flexibility.

Single-use bag bioreactor (any modality)

Sartorius Biostat STR, Thermo HyPerforma, Cytiva Xcellerex, Merck Mobius. The bag vendor has already chosen the DO sensor — usually a PreSens spot or Hamilton VisiFerm SU adapter. Your job is confirming compatibility with your control system.

Single-use

Commercial mAb >5,000 L

Blockbuster mAb demanding 500+ kg per year requires 10,000-25,000 L stainless steel vessels. Single-use bags hit a scale ceiling around 6,000 L; reusable DO probes are the only viable choice.

Reusable

CDMO multi-product facility

Running 5-10 different clients' products in the same suite. Eliminating cleaning validation between products is worth more than the per-batch bag cost. Single-use is effectively the only operating model.

Single-use

High-throughput microbial (>100 batches/yr)

Industrial microbial fermentation at 1,000-10,000 L running 100-200 batches per year per vessel. Per-batch single-use costs (bag + consumables) dominate economics at this frequency. Reusable stainless wins decisively.

Reusable

Real-world use cases

Four representative bioprocess setups and which sensor approach each team converged on.

CAR-T autologous · 2-10 L

Single-use (patient isolation)

Every patient gets a dedicated single-use bag with pre-integrated PreSens optical spot. No shared hardware means zero cross-patient contamination risk — a regulatory non-negotiable for autologous therapy.

AAV HEK293 · 200 L

Single-use (bag-integrated)

Sartorius Biostat STR 200 L ships with a gamma-pre-sterilised PreSens spot in the bag. 4-hour batch turnaround without CIP/SIP supports the high batch count of viral-vector campaigns.

Commercial mAb · 12,500 L SS

Reusable (Hamilton VisiFerm DO Arc)

Dedicated mAb facility running 150 batches/year at 12,500 L stainless. Reusable probe amortises to <£1 per batch; single-use at this scale is infeasible (no 12,500 L bags exist).

E. coli microbial · 10,000 L SS

Reusable (Mettler InPro 6800)

Industrial recombinant protein fermentation, 200 batches/year. Fast polarographic response time matters for oxygen-limited induction control; single-use at this scale does not exist.

Not sure whether single-use or reusable fits your bioreactor?

Answer a few quick questions and get ranked sensor recommendations tailored to your scale, modality, vessel type, and budget — covering single-use spots, reusable probes, and PAT analytics.

Open the Sensor Selection Tool

Cost and lifecycle considerations

The sensor cost is a small fraction of the total single-use vs reusable decision

A single-use DO sensor costs £30-£80 per batch (bundled in the bag); a reusable probe amortises to under £10 per batch at high throughput. But the vessel decision (SUB vs SS) drives CapEx by tens of millions, OpEx by millions per year, and facility footprint by 30-50% — dwarfing the sensor difference. If you're studying this at the sensor level, you've usually already made the vessel decision upstream.

That said, here is the rough per-channel economics over a 5-year campaign at two representative throughputs:

Scenario	Single-Use	Reusable
Low throughput (30 batches/yr, 1 vessel, 5 yr)	~£5,000-£12,000 total	~£3,500 + 5 yr consumables ~£5,000
High throughput (150 batches/yr, 1 vessel, 5 yr)	~£25,000-£60,000 total	~£3,500 + 5 yr consumables ~£8,000
Cleaning validation effort	None	Per-product CIP/SIP qualification
Batch turnaround time (sensor-driven)	4-8 hours (bag swap)	8-24 hours (CIP/SIP + probe prep)

Vendor landscape

Single-use DO sensor providers (bag + sensor combinations)

Sartorius Biostat STR: 50 L to 2,000 L SUBs with pre-integrated PreSens optical DO spots at the bag factory.
Thermo Fisher HyPerforma: 50 L to 2,000 L SUBs; offers bags with either PreSens or Hamilton VisiFerm SU spots depending on configuration.
Cytiva Xcellerex: 10 L to 2,000 L single-use; also pre-integrates optical DO at manufacture.
Merck Mobius: 50 L to 2,000 L SUBs targeting mAb and viral-vector applications.

Single-use DO sensor makers (OEM)

PreSens SP-PSt3 / SP-PSt6: dominant OEM sensor spot supplier to most major bag vendors. Gamma-compatible, pre-calibrated by batch.
Hamilton VisiFerm SU: Hamilton's single-use probe variant with pre-integrated sterile adapter approach.
PyroScience FP-O2: OEM optical O₂ sensor spots for custom bag integrations and µbioreactor applications.
Scientific Bioprocessing: single-use optical DO for shake flasks and small-scale single-use vessels.

Reusable DO probe vendors

Hamilton VisiFerm DO Arc: market-leading insertable optical DO probe for reusable stainless steel bioreactors. See the VisiFerm DO Arc literature review for peer-reviewed deployment evidence.
Mettler Toledo InPro 6950i / 6050: optical and polarographic variants with ISM digital ecosystem.
Endress+Hauser Memosens COS81D / COS22D: optical and polarographic options in the Memosens digital platform.
Broadley-James OxyProbe: polarographic DO with bioprocess pedigree, often bundled with their pH probes.

Frequently asked questions

What is the difference between single-use and reusable DO sensors for bioreactors?

For bioreactor applications specifically (not pulse oximeters or automotive): single-use DO sensors are gamma-sterilised optical patches pre-integrated into disposable bioreactor bags by the bag vendor (Sartorius Biostat STR, Thermo HyPerforma, Cytiva Xcellerex). Reusable DO sensors are insertable probes — typically Hamilton VisiFerm, Mettler Toledo InPro, or equivalent — that fit standard PG13.5 ports in stainless steel bioreactors and survive autoclave and CIP/SIP cycles. The choice is almost entirely driven by vessel type: if you run a single-use bag, you use the sensor the bag comes with; if you run reusable stainless, you use a reusable probe.

Are single-use DO sensors less accurate than reusable?

No. Modern single-use optical DO spots (PreSens SP-PSt3, Hamilton VisiFerm SU, PyroScience FP-O2) use the same luminescence-quenching chemistry as their reusable probe counterparts and achieve equivalent accuracy specifications — typically ±0.1% DO in the 0-100% air-saturation range. The functional evaluation study in BIOne single-use bioreactors (American Pharmaceutical Review) showed single-use optical spots and invasive reusable probes track within ±2% during typical CHO fed-batch runs.

Why are single-use bioreactor bags pre-integrated with DO sensors?

Because adding a probe after bag assembly breaches sterility. The bag vendor glues the sensor spot to the inside wall during bag manufacturing, then gamma-sterilises the entire assembly. On site, the user simply clamps an external fiber-optic reader to the outside of the bag window and starts measuring — no port, no sterilisation, no calibration beyond reading the factory batch code. This workflow is fundamentally why single-use bioreactors achieved rapid adoption in cGMP mammalian manufacturing.

When does reusable become cheaper than single-use for DO sensing?

Per-batch cost crossover depends on vessel size and batch frequency. For bags up to 2,000 L at 20-30 batches/year, single-use bag economics usually win. Above 5,000 L or at 100+ batches/year on one vessel, a reusable probe amortises to near-zero per-batch cost while the single-use sensor remains bundled at £30-£80 per bag. At a dedicated cGMP mAb facility running 150 batches/year at 10,000 L, reusable is dramatically cheaper; at a multi-product CDMO running 20 batches/year across 6 products, single-use wins on contamination-risk avoidance alone.

Can you retrofit a reusable DO probe into a single-use bag?

Only with vendor-specific sterile adapters designed for this purpose. Hamilton offers VisiFerm SU, a single-use variant that inserts into a pre-integrated adapter in the bag. But most users who need reusable-probe functionality in a single-use vessel find that the adapter cost plus probe cost exceeds the savings over the bag-integrated optical spot approach. The practical answer: if you need reusable probe features, use a reusable bioreactor.

What is the validation effort difference between single-use and reusable DO sensors?

Single-use requires extractables and leachables (E&L) studies for the sensor spot plus bag-film combination, plus gamma-irradiation dose validation — typically done once by the bag vendor and accepted via their Drug Master File. Reusable requires IQ/OQ/PQ for the probe, CIP/SIP cleaning validation, and periodic re-qualification of the probe over its lifetime. Single-use front-loads validation cost; reusable spreads it across the probe's 50-300 batch lifetime. Total effort is roughly similar over a 5-year campaign, but single-use gets to first-batch faster.

Are single-use DO sensors limited to optical technology?

Effectively yes. Polarographic (Clark-cell) sensors require an internal electrolyte and gas-permeable membrane — neither of which survives gamma sterilisation reliably. All commercial single-use bag DO sensors use optical luminescence quenching (PreSens SP-PSt3/PSt6, Hamilton VisiFerm SU, PyroScience, Scientific Bioprocessing). For bioreactor applications needing polarographic response speed, you must use a reusable stainless or glass vessel.

Which is more environmentally sustainable?

Reusable wins on a single-batch basis because the sensor is amortised across many batches. Single-use generates 50-100 kg of plastic waste per batch (the entire bag assembly) but avoids 5,000-10,000 L of water and CIP chemicals per cleaning cycle plus the steam generation for SIP. Full lifecycle analysis is process-dependent; at low batch counts (<30/yr), single-use has a competitive or even favourable carbon footprint because cleaning utilities dominate. At high batch counts (>100/yr), reusable is materially greener.

Resources and references

Busse et al. 2017 — Sensors for disposable bioreactors (Engineering in Life Sciences) — peer-reviewed review of single-use sensor integration, covering DO, pH, and biomass across major bag formats.
APR — Functional Evaluation of DO Sensors in BIOne Single-Use Bioreactor — head-to-head field study of single-use spots against invasive reusable probes.
Hamilton — VisiFerm SU and Single-Use DO Sensors — vendor reference on single-use probe integration with sterile bag adapters.
PreSens — Optical O₂ Sensor Products Overview — vendor reference on SP-PSt3/PSt6 sensor spots and OEM bag integration workflow.