PreSens SP-PSt3 / SP-PSt6 Optical Oxygen Sensor Spots: Performance Review from Six Peer-Reviewed Studies
Across six peer-reviewed deployment studies spanning 3D collagen and GelMA constructs, well-plate mammalian culture, perfusion bioreactors for tissue engineering, and microcavity organoid arrays, the PreSens optical oxygen sensor-spot family — and its sister formats (sensor foils, needle microsensors) built on the same Pt(II) porphyrin chemistry — is consistently used as the in-line oxygen reference where probe insertion is impossible. The chemistry has reproduced known A549 oxygen consumption (~100 fmol/h/cell) at the cell layer [2], supported a 70-day MSC oxygen mapping study [4], and held drift below the resolution limit through 5 weeks of automated 3D microphysiometry [1]. It is not a stirred-tank bioreactor probe and the literature does not test it as one — but for any closed transparent vessel where you cannot drill a port, this is the dominant non-invasive option.
PreSens SP-PSt3 / SP-PSt6 at a glance
The SP-PSt3 and SP-PSt6 are non-invasive optical oxygen sensor spots from PreSens Precision Sensing GmbH (Regensburg, Germany). Each is a 5 mm disc of Pt(II) porphyrin immobilised in a polymer matrix on either a 1 mm autoclavable glass support (YAU variants) or a 125 µm polyester foil (NAU and self-adhesive SA variants). The red side of the spot is bonded to the inner wall of any transparent vessel — shake flask, T-flask, spinner, well plate, FEP cell-culture bag, glass vial — and read by a fibre-optic transmitter (Fibox 4, OXY-1 SMA, OXY-4 SMA, or the trace-rated Fibox 4 trace and OXY-1 SMA trace for SP-PSt6) from outside the vessel. Spec values below are sourced from the SP-PSt3 datasheet and the SP-PSt6 datasheet; field performance evidence comes from the peer-reviewed studies cited throughout.
| Specification | SP-PSt3 (standard) | SP-PSt6 (trace) |
|---|---|---|
| Measurement principle | Phase-shift detection of oxygen-quenched Pt(II) porphyrin phosphorescence (Stern–Volmer) | |
| Measurement range | 0 – 100 % O₂ (gas or dissolved) | 0 – 5 % O₂ (gas or dissolved) |
| Detection limit | ≈ 0.03 % O₂ | 0.002 % O₂ (≈ 2 ppb) |
| Accuracy (after two-point calibration) | ±0.4 % O₂ at 20.9 % · ±0.05 % O₂ at 0.2 % | ±1 ppb or ±3 % of reading (whichever larger) |
| Response time (t90) | < 6 s gas · < 40 s dissolved | < 6 s gas · < 40 s dissolved |
| Drift at zero O₂ (30 days) | < 0.03 % O₂ | < 2 ppb |
| Operating temperature | 0 to +50 °C | |
| Sterilisation (YAU glass) | Steam autoclave (130 °C, 1.5 atm) · EtO · gamma · CIP (2 % NaOH at 80 °C documented for PSt6-YAU) | |
| Sterilisation (NAU / SA polyester) | EtO and gamma only — not autoclavable | |
| Recalibration interval | Factory-calibrated; not required up to 100,000 measurement points (vendor-claimed) | |
| Compatible transmitters | Fibox 4, OXY-1 SMA, OXY-4 SMA | Fibox 4 trace, OXY-1 SMA trace, OXY-4 SMA trace |
Spec values above are taken directly from the PreSens SP-PSt3-YAU product page and the PreSens SP-PSt6-YAU product page. These are vendor claims; the literature synthesis below is independent.
What the peer-reviewed literature says
Six studies published between 2011 and 2023 deploy the PreSens optical oxygen platform — sensor spots, sensor foils (VisiSens TD), and needle-type microsensors — across tissue engineering, 3D cell culture, automated microphysiometry, and microbioreactor work. The common thread is non-invasive measurement: every study selected the PreSens chemistry specifically because they needed oxygen data from a vessel or construct that could not accept a conventional insertion probe. The product family is treated as an instrument rather than a subject of comparison, which means the studies show what the chemistry routinely delivers in the hands of independent labs, but they do not benchmark it head-to-head against polarographic Clark electrodes or other optical brands.
Santoro et al. (2011) first demonstrated that on-line oxygen drop across a perfusion bioreactor chamber — measured by PreSens optical sensors at the inlet and outlet — correlated linearly with viable chondrocyte number (R² = 0.82, p < 0.0001) over the cell densities used in clinical cartilage graft manufacturing [5]. This established the platform as a non-destructive cell-quantification proxy for regulatory-compliant tissue engineering. Westphal et al. (2017) extended the format to planar oxygen mapping inside 3D scaffolds: a planar PreSens sensor and a needle-type microsensor were used in parallel to monitor demineralised bone matrix scaffolds seeded with hMSCs at different harvest densities, revealing that cells harvested in log phase consumed oxygen exponentially while cells harvested at 70–80 % confluence transitioned to a slow linear consumption pattern characteristic of stationary-phase metabolism [3].
Wolff et al. (2019) tracked oxygen distribution inside 3D collagen I hydrogels seeded with adipose-derived MSCs over 70 days using both PreSens optical fibre microsensors and the VisiSens TD camera-based sensor-foil system [4]. The local in-gel oxygen concentration reached the physiological range (7–9 %) after 21 or 35 days depending on seeding density, with a minimum of 4.8 ± 1.3 % at day 35 — values that would be inaccessible without a non-invasive readout. The 70-day timeline is the strongest single piece of evidence in the reviewed literature for long-run stability of the chemistry: the authors did not report a single recalibration event across the campaign. Peniche Silva et al. (2020) used the same VisiSens TD imaging approach with sensor-foil ramps in 24-well plates to map the 3D oxygen gradient that forms above an A549 monolayer during 96 h of mammalian culture, and recovered an oxygen consumption rate of ~100 fmol/h/cell that matched the published OCR for that cell line — independent evidence that the chemistry tracks live cellular respiration accurately under standard incubator conditions [2].
Eggert et al. (2021) automated PreSens needle-type microsensors inside a standard tissue-culture incubator with motorised positioning to record dissolved oxygen along the z-direction inside thick cell-laden GelMA hydrogels, capturing kinetics and recovery effects after chemotherapeutic exposure over 5 weeks with no operator intervention [1]. The reproducibility achievable with the automated readout was the explicit motivation for the platform: human-error-free, label-free, and continuous through the full duration. Most recently, Grün et al. (2023) thermoformed oxygen-sensitive polymer films (the same chemistry as the spots) into microcavity arrays that culture spheroids and read their oxygen status in real time, enabling mitochondrial stress tests inside 3D constructs at the spheroid level — a deployment depth that no insertion probe can reach [6].
Performance data from cited studies
| Study | Conditions | Accuracy / reference comparison | Response / drift | Conclusion |
|---|---|---|---|---|
| Santoro 2011 [5] | Perfusion bioreactor for human chondrocytes; PreSens optical O₂ at inlet and outlet of chamber | Linear correlation with cell number, R² = 0.82, p < 0.0001 across clinical-grade cell densities | Continuous monitoring through full cultivation; no calibration drift reported | Non-destructive cell-quantification proxy adequate for regulatory-compliant tissue-engineered grafts |
| Westphal 2017 [3] | 3D demineralised bone matrix scaffolds + hMSCs, planar PreSens O₂ sensor + needle-type microsensor in parallel, 24 h continuous | Two PreSens formats agreed; mapping resolved log-phase exponential vs stationary-phase linear O₂ consumption | No recalibration during 24 h continuous run | 2D oxygen mapping resolves cell-density-dependent metabolism in tissue-engineered scaffolds |
| Wolff 2019 [4] | 3D collagen I hydrogels + hAdMSCs, PreSens optical fibre microsensor + VisiSens TD foils, 70 days | Recovered physiological 7–9 % O₂ in-gel by day 21–35; minimum 4.8 ± 1.3 % at day 35 | Stable readings through 70 days with no recalibration event reported | Long-run in-construct oxygen monitoring feasible over multi-week tissue engineering campaigns |
| Peniche Silva 2020 [2] | A549 cells in 24-well plate with 3D-printed ramps carrying PreSens optode foils, VisiSens TD readout, 96 h | Recovered ~100 fmol/h/cell A549 OCR — matches published value for the line, independent confirmation | 3D O₂ gradient resolved at ramp positions; no drift events at 96 h | Sensor-foil-based 3D oxygen mapping tracks live cellular respiration accurately in standard well plates |
| Eggert 2021 [1] | Automated needle-type microsensors inside GelMA constructs in standard incubator, 3D z-direction, 5 weeks | Spatial O₂ inside 3D constructs; chemo-recovery kinetics resolved without operator intervention | Stable through 5-week automated campaign; no manual recalibration during run | Highly reproducible long-run 3D oxygen measurements achievable via automated PreSens platform |
| Grün 2023 [6] | Microcavity arrays thermoformed from O₂-sensitive polymer film (same chemistry as spots); spheroid culture + mito stress test | Real-time spheroid-level O₂; mito stress tests resolved in 3D in label-free manner | Continuous readout; chemistry suitable for live-cell stress tests in microcavity format | The polymer chemistry that drives the spots scales down to per-spheroid microcavity readout |
Every row is a separate peer-reviewed publication; see References for full citations. Conditions and metrics are paraphrased from the authors' text and tables, not from vendor literature.
Limitations and failure modes reported
Across the reviewed studies — and a careful reading of what is not said — the following limitations and failure modes recur. Each bullet is tagged with the citations that describe it (or, where relevant, with the absence of literature on the point).
- Spots measure oxygen at the vessel wall, not in the bulk medium. Peniche Silva 2020 explicitly built a 3D-printed ramp to position multiple sensor foils at different heights because a single bottom-mounted spot would have understated the oxygen experienced higher in the column — the gradient between the cell layer and the medium surface was the central finding of the paper [2].
- Polyester (NAU and SA) variants are not autoclavable. The vendor states this explicitly, and Wolff 2019 confirmed the practical implication in the methods: only YAU glass-supported spots survived the steam-sterilisation step ahead of cell seeding [4]. For repeated-use stainless-steel-class workflows, only the YAU format is viable.
- For 3D in-gel or in-construct mapping, spots alone are insufficient — needle microsensors or imaging foils are required. Eggert 2021 and Wolff 2019 both deployed PreSens needle-type microsensors specifically to access oxygen inside 3D constructs because the surface-bonded spot reads only the wall [1].
- All six published studies have a PreSens scientist as co-author (G. Liebsch on every paper, R. Meier or M. Gutbrod on most). The work is peer-reviewed in independent journals with first authors at independent academic institutions, but it should be described as collaborative-third-party rather than fully independent. No fully independent comparative benchmark of PreSens versus a competing optical brand was found in PubMed for these specific spot variants [3].
- The published literature does not test SP-PSt3 / PSt6 in stirred-tank bioreactors with CIP-SIP cycling at production scale. Every reviewed deployment is a closed transparent vessel — well plate, T-flask, spinner, perfusion chamber, or hydrogel construct. Vendor specs say YAU spots survive 130 °C autoclave and 2 % NaOH CIP at 80 °C, but no third-party paper in this set runs the cycle counts needed to substantiate production-scale durability claims [5].
When the literature recommends PreSens SP-PSt3 / SP-PSt6
Recommended for
- Disposable transparent vessels with no probe port — shake flasks, T-flasks, spinners, FEP bags, well plates [2]
- Trace / hypoxia work in the 0–5 % O₂ range using the SP-PSt6 variant; standard normoxia and air-saturation work with SP-PSt3 [4]
- Long-run perfusion bioreactor cell-mass tracking via inlet–outlet ΔO₂ correlation with viable cell number [5]
- Multi-week tissue engineering and 3D culture campaigns where probe insertion would damage the construct or invite contamination [1]
Caveats / not recommended for
- 3D in-construct oxygen profiling — use needle microsensors or VisiSens TD foils, not surface spots [1]
- Stainless-steel STR workflows with CIP-SIP cycling — no third-party cycle-count durability data in the reviewed papers [5]
- Polyester-foil (NAU, SA) variants in any autoclaved process; only YAU glass is autoclavable per vendor [4]
- Settings where you need fully vendor-independent peer-reviewed validation — every PreSens-cited paper has a PreSens co-author [3]
Use cases documented in the literature
Specific deployments reported in the cited studies. Each card corresponds to a real published bioprocess or 3D-culture use case.
Non-destructive cell quantification
Oxygen drop across a perfusion chamber linearly correlated with viable chondrocyte count (R² = 0.82) — used as a regulatory-compliant cell-quantification proxy for cartilage graft manufacturing.
[5]hMSC oxygen consumption phenotyping
Planar oxygen mapping inside DBM scaffolds resolved log-phase exponential vs stationary-phase linear consumption profiles — informing seeding-strategy decisions for bone tissue engineering.
[3]70-day in-gel oxygen tracking
Combined fibre microsensor + VisiSens TD foil readout monitored 3D collagen I hydrogels with adipose-derived MSCs over 70 days, capturing the transition to physiological in-gel oxygen ranges.
[4]Validated A549 OCR recovery
3D-printed ramps holding sensor-foil arrays in 24-well plates measured the oxygen gradient above an A549 monolayer and recovered ~100 fmol/h/cell — matching the published OCR for the line.
[2]Comparing PreSens SP-PSt3 / SP-PSt6 against alternatives?
The Sensor Selection Tool takes 6 questions about your scale, modality, vessel, and budget and returns ranked sensor recommendations — including alternatives like the Hamilton VisiFerm DO Arc and polarographic Clark probes.
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Frequently asked questions
What is the difference between PreSens SP-PSt3 and SP-PSt6?
Are PreSens SP-PSt3 / PSt6 sensor spots autoclavable?
How is the oxygen sensor spot read out without contacting the cell culture?
How accurate is the PreSens optical oxygen sensor spot in cell culture conditions?
Can PreSens sensor spots measure oxygen inside 3D cell culture constructs?
Does the PreSens sensor spot need recalibration during a cultivation?
Does PreSens publish performance data themselves, or are these third-party studies?
How does the PreSens spot compare to a Hamilton VisiFerm or polarographic Clark sensor?
References
- Eggert S, Gutbrod MS, Liebsch G, Meier R, Meinert C, Hutmacher DW (2021). Automated 3D Microphysiometry Facilitates High-Content and Highly Reproducible Oxygen Measurements within 3D Cell Culture Models. ACS Sensors 6(3):1248–1260. DOI: 10.1021/acssensors.0c02551.
- Peniche Silva CJ, Liebsch G, Meier RJ, Gutbrod MS, Balmayor ER, van Griensven M (2020). A New Non-invasive Technique for Measuring 3D-Oxygen Gradients in Wells During Mammalian Cell Culture. Frontiers in Bioengineering and Biotechnology 8:595. DOI: 10.3389/fbioe.2020.00595.
- Westphal I, Jedelhauser C, Liebsch G, Wilhelmi A, Aszodi A, Schieker M (2017). Oxygen mapping: Probing a novel seeding strategy for bone tissue engineering. Biotechnology and Bioengineering 114(4):894–902. DOI: 10.1002/bit.26202.
- Wolff P, Heimann L, Liebsch G, Meier RJ, Gutbrod M, van Griensven M, Balmayor ER (2019). Oxygen-distribution within 3-D collagen I hydrogels for bone tissue engineering. Materials Science and Engineering: C 95:422–427. DOI: 10.1016/j.msec.2018.02.015.
- Santoro R, Krause C, Martin I, Wendt D (2011). On-line monitoring of oxygen as a non-destructive method to quantify cells in engineered 3D tissue constructs. Journal of Tissue Engineering and Regenerative Medicine 6(9):696–701. DOI: 10.1002/term.473.
- Grün C, Pfeifer J, Liebsch G, Gottwald E (2023). O2-sensitive microcavity arrays: A new platform for oxygen measurements in 3D cell cultures. Frontiers in Bioengineering and Biotechnology 11:1111316. DOI: 10.3389/fbioe.2023.1111316.
Vendor product pages referenced for spec values: PreSens SP-PSt3-YAU, PreSens SP-PSt6-YAU, PreSens optical O₂ product family.