SporeScope
Reliable Endospore detection. In Real time.
We're here to make spore monitoring smarter, faster, and more precise.
SporeScope is designed to revolutionize the way we study bacterial spore behavior by providing a real-time, controllable microenvironment that mimics natural conditions. By integrating microfluidics with a hydrogel matrix, our platform enables precise delivery of nutrients and stress signals while allowing high-resolution imaging of germination dynamics. This tool addresses a critical gap in monitoring dormant-to-active state transitions in spores, which has implications for agriculture, medicine, and environmental microbiology.
Key Features of Our Lab-on-a-Chip
True 3D Monitoring Environment
Unlike other microfluidic systems that flatten cells into a 2D analysis plane, SporeScope preserves a three-dimensional hydrogel matrix. This enables spatially accurate, realistic simulation of micro-environments where spores remain immobilised without compression.
Real-Time, High-Resolution Imaging Compatibility
SporeScope supports real-time imaging of germination using confocal and widefield fluorescence microscopy, with RFP-labelled spores tracked as they germinate. This live observation of biological events at single-cell resolution within the matrix sets it apart from static or batch-analysis methods.
Dual-Channel Support Fluidics with Solute Exchange Barrier
The chip includes dual support fluidic channels flanking the hydrogel chamber, allowing continuous nutrient flow and waste removal. A semi-permeable membrane at the chamber–channel interface permits selective solute diffusion (O₂, nutrients), while keeping the hydrogel physically sealed — preventing cross-contamination or leakage.
Modular & Single-Use Biocompatible Design
Constructed from optically transparent PDMS, the chip is biocompatible, disposable, and follows international biosafety disposal standards. The modular I/O system with interchangeable ports supports standard fittings (e.g., Luer-lock or ¼-28), enhancing usability across labs without compromising sterility.
Validated through experiments
Real data. Proven performance.
Real-Time Visualisation of Germination
Spores of Bacillus subtilis 168 were embedded in a 2% (w/v) alginate hydrogel matrix within the central chamber of the device. Nutrient broth flowed through the flanking support fluidic channels to simulate environmental changes. RFP-labelled spores were imaged using widefield fluorescence microscopy, allowing real-time observation of the germination process as spores transitioned from phase-bright to phase-dark — indicating successful activation under flow.
Single-Cell Resolution Tracking
ImageJ and the MTrackJ plugin were used to track individual RFP-labelled spores within the hydrogel. Key quantitative metrics, including average distance between tracked points (D2P ≈ 2.6–2.8 px) and distance from start (D2S ≈ 71–79 px), confirmed the device's ability to support accurate, single-cell resolution tracking during germination.
Distinguishing Environmental Responses
Spores were exposed to high (1×) and low (0.1×) nutrient broth concentrations. The chip enabled clear differentiation in germination behavior: spores in high nutrient conditions germinated rapidly and displaced further (mean D2S ≈ 79 px), while those in low nutrient conditions showed delayed or limited activation (mean D2S ≈ 71 px). This demonstrates the platform's ability to detect phenotypic responses to environmental stimuli.
Fluorescence-Specific Detection
To confirm signal specificity, experiments were conducted with non-fluorescent B. subtilis 395 under the same imaging conditions. These controls exhibited no detectable signal, verifying that the observed fluorescence was due to RFP expression and not background autofluorescence — ensuring reliable visualisation of germination events.
How it works
Embed the spores
Endospores are suspended in a prepolymer solution consisting of 10% (w/v) PEGDA and 0.1% (w/v) Irgacure 2959, a photoinitiator. The solution is prepared in sterile water and mixed thoroughly to ensure even distribution. This mixture is injected into the central chamber of the PDMS device, where PEGDA’s optical clarity and biocompatibility create a stable, observable matrix.
Seal and Cure
The device is placed under a UV light source (365 nm) for approximately 60 seconds to initiate photopolymerisation. The UV exposure crosslinks the PEGDA, forming a solid hydrogel that immobilises the spores in three dimensions. This process preserves spatial localisation, prevents movement during flow, and maintains compatibility with downstream imaging.3. Introduce Environmental Stimuli
Introduce Environmental Stimuli
Nutrient media—either 1× or 0.1× LB broth—is introduced into the flanking side channels. These channels allow nutrients to diffuse into the hydrogel, exposing the immobilised spores to controlled microenvironmental conditions. This setup enables direct comparison of germination responses under different nutrient levels without disturbing the spore locations.
Real-Time Imaging
The chip is mounted onto a widefield fluorescence microscope. Spores expressing GFP are imaged over time to observe germination, indicated by the transition from phase-bright to phase-dark appearance and an increase in fluorescence. PEGDA’s optical transparency supports high-resolution, single-cell-level imaging throughout the gel.
Analyse and Interpret
Time-lapse images are analysed using ImageJ software. Individual spores are tracked using the MTrackJ plugin, and quantitative metrics like Distance Between Points (D2P) and Distance to Start (D2S) are extracted. This analysis provides a high-resolution view of germination kinetics and spatial behaviour under different environmental inputs.