CAVIGEN Knowledge Hub –
3D cell culture, organoid and oxygem measurement resources

Microcavities are defined, micrometre-scale wells formed in thin polymer films by microthermoforming. They act as individual “niches” in which cells aggregate and grow into 3D spheroids or organoids.
Because the geometry of the microcavities is controlled, they help to achieve more uniform 3D structures and to standardise 3D cell culture conditions across experiments.

MicroSphere is designed for standardised 3D spheroid and organoid culture with good microscopy access. PoroSphere adds controlled porosity for perfusion, co-culture and barrier models. SensoSphere enables optical oxygen measurement directly in the microcavities.
In more detail, MicroSphere uses non-porous microcavities with defined diameter to generate spheroids of similar size. PoroSphere is based on ion-track etched and chemically treated films to create well-defined pores for fluid flow and cell migration. SensoSphere combines these microcavities with oxygen-sensitive and reference fluorophores; the dynamic fluorescence quenching of the sensor dye by oxygen allows ratiometric read-out of pericellular O₂ levels in real time.

SensoSphere uses oxygen-sensitive fluorophores, where oxygen quenches the fluorescence signal, combined with a reference dye for ratiometric read-out. This allows you to calculate pericellular oxygen concentrations in real time.
The underlying principle is dynamic fluorescence quenching: the O₂-sensitive dye is excited at a defined wavelength, and in the absence of oxygen it emits a strong fluorescence signal. Collisions with dissolved oxygen molecules lead to a non-radiative energy transfer and reduce the fluorescence intensity. By measuring the ratio between sensor and reference fluorescence, and applying a two-point calibration, local oxygen concentrations can be derived with high sensitivity, even at low oxygen levels.

No. CaviSphere does not actively control oxygen; it does not include gas-control hardware or closed-loop regulation. SensoSphere enables you to measure oxygen profiles in 3D, not to regulate them directly.
The platform supports more physiologically relevant 3D models by combining standardised microcavity-based 3D cultures with pericellular oxygen measurement. The oxygen-sensitive fluorophores in SensoSphere respond to local oxygen concentration, but any control of oxygen (for example through incubator settings, gas mixing or perfusion conditions) remains within your existing equipment. The measurement data can, however, be used to refine and document physioxia-oriented culture conditions.

CaviSphere inserts and films are compatible with standard inverted and upright microscopes and with typical cell biology workflows. SensoSphere can be read out using optical oxygen measurement devices and fluorescence microscopes.
MicroSphere and PoroSphere support brightfield and fluorescence imaging and can be combined with standard plate readers for endpoint assays. SensoSphere sensor arrays have been validated in combination with commercial oxygen measurement systems (for example from PreSens) and with confocal and widefield fluorescence microscopes. The sensor chemistry is designed to work in aqueous media over a broad pH range and typical cell culture temperatures, so that you can integrate oxygen measurements into existing imaging and read-out setups.

CaviSphere helps you to make 3D models more reproducible and to document oxygen conditions, which is important for New Approach Methodologies (NAMs) and 3R strategies.
Standardised microcavities improve control over spheroid and organoid size, and SensoSphere adds quantitative oxygen measurement at the level of the 3D culture. This combination facilitates transparent reporting of culture conditions, supports the design of physioxia-oriented protocols and can contribute to in vitro models with better predictive power compared to traditional 2D systems and hyperoxic conditions.

CaviSphere® is a microcavity-based 3D cell culture platform for spheroids and organoids, available as ready-to-use inserts and as films for integration into custom devices.
In more detail, all variants share a common microcavity architecture with up to 600 cavities/cm², manufactured by microthermoforming of polymer films. MicroSphere is optimised for imaging and standard assays, PoroSphere adds defined porosity for perfusion and co-culture, and SensoSphere integrates optical oxygen sensor dyes for spatially resolved oxygen measurements in 3D.

CaviSphere is available as microstructured films (“sheets”) and as pre-assembled inserts that fit into standard multiwell plates. Films are offered in different microcavity layouts and diameters, and can be cut and integrated into custom devices. Inserts combine defined microcavity fields with a convenient frame for routine handling.
The exact formats (microcavity diameters, number of cavities, materials such as PC, PS or PLA) are documented in the CaviSphere data sheets. If you are unsure which configuration fits your experiment, we recommend using our configuration tools or contacting us directly.

The optimal configuration depends on your cell type, assay read-out and culture duration. In general, smaller microcavities support smaller, more numerous spheroids, while larger cavities can host bigger organoids or more complex 3D structures.
To help you choose, we provide configuration guidance and tools that map typical applications (e.g. toxicology, Organ-on-Chip, oxygen measurement) to suitable MicroSphere, PoroSphere or SensoSphere formats. You can also contact us with your experimental requirements so we can suggest a starting point.

Inserts are ideal if you want a ready-to-use format that fits directly into standard multiwell plates and requires minimal engineering effort. Films are the better choice if you are developing custom devices or Organ-on-Chip systems.
CaviSphere inserts (e.g. 4-well inserts for 12-well plates) are pre-assembled units that can be handled like other cell culture inserts and support straightforward workflows in existing incubators, microscopes and plate readers. Films are flat microstructured foils that can be cut, bonded and integrated into microfluidic chips, bespoke chambers or Organ-on-Chip cartridges, while maintaining the same microcavity geometry and, for SensoSphere, the same optical oxygen sensor chemistry.

Yes. We provide handling protocols for all CaviSphere products, covering topics such as sterilisation, coating, cell seeding, medium changes and imaging.
These protocols are available as downloads and are continuously updated based on internal work and feedback from collaborating labs. If you have specific questions or an unusual setup, you can contact us directly for support.

CaviSphere products are suitable for a wide range of 3D cell culture models, including spheroids, organoids and 3D co-cultures. Typical applications include tumour spheroids, liver spheroids, stem-cell-derived organoids and barrier models.
Microcavity arrays can be used both in simple static culture (e.g. in multiwell plates) and as components in more complex microfluidic or Organ-on-Chip setups. PoroSphere variants are particularly useful when perfusion, co-culture or migration are part of the experimental design.

MicroSphere is optimised for microscopy and the generation of spheroids for long-term 3D cell culture. It is typically used for imaging-heavy assays, toxicology screens and standard 3D culture workflows where reproducible spheroid size is important.
PoroSphere is useful for working with dynamic cell cultures and co-cultures. The defined porosity supports perfusion, barrier formation and cell migration, making it attractive for Organ-on-Chip developers and advanced in vitro models with flow.

Yes, it is possible to cultivate enough cells in CaviSphere microcavity arrays to perform PCR-based analyses.
Depending on the cell type, seeding density and culture duration, microcavity arrays can generate a sufficient total cell number for downstream molecular assays. The exact yield will depend on your specific setup, but PCR is a realistic endpoint for many 3D culture configurations.

The optimal cell number depends on your cell type and the planned culture duration, but as a starting point we generally recommend seeding around 1×10⁵ cells per sheet/insert for an initial test.
This seeding density has proven useful in first experiments with hepatoma cell lines and similar adherent cells. You can then adjust the cell number up or down based on observed spheroid size, viability and assay requirements.

Yes, staining of spheroids generated in CaviSphere microcavities is possible and commonly used.
Live/dead staining, nuclear dyes and other fluorescent markers can be applied directly in the cavities. Staining within the microcavities avoids additional handling steps and preserves the spatial context of the 3D structures for imaging.

Compared to 2D cultures, staining in 3D spheroids requires more time for the dyes to penetrate into the core of the aggregate.
In practice, the incubation time of the staining solution should be extended. We recommend up to 24 hours to ensure that even larger spheroids are homogeneously stained, especially when using nuclear or viability dyes.

There is no fixed limit to culture time in CaviSphere microcavities; it mainly depends on the number of cells seeded, their proliferation behaviour and the nutrient supply in your system.
In static cultures, medium changes and appropriate seeding densities help maintain viable spheroids over several days to weeks. In perfused systems or Organ-on-Chip setups, longer culture periods may be possible, as long as oxygen and nutrients remain within a suitable range for your cell type.

Choose inserts when you want a straightforward, plate-based 3D culture setup with minimal integration effort, for example for toxicology, imaging or routine assays. Choose films when you are incorporating CaviSphere into a custom device, microfluidic system or Organ-on-Chip platform.
Both formats support spheroid and organoid formation; PoroSphere films add porosity for perfusion and co-culture, and SensoSphere films enable integrated oxygen measurement in 3D. Inserts are often the best entry point for first experiments, while films offer maximum flexibility for advanced users.