Top FAQs on Spatial Metabolomics Sample Preparation
Spatial metabolomics integrates mass spectrometry imaging (MSI) and metabolomics to directly reveal the spatial distribution and dynamic changes of metabolites in biological samples. With core advantages such as high resolution, in situ non-destructive detection, and multi-omics integration, this technology is applicable to diverse sample types, including clinical tumor tissues, animal organs, and plant leaves. By leveraging techniques like cryosectioning and matrix coating, spatial metabolomics preserves the native state and spatial information of metabolites, enabling comprehensive analysis across qualitative, quantitative, and spatial dimensions. This makes it a powerful tool for studying disease mechanisms, crop improvement, and ecological interactions.
Sample Collection Requirements
1) Size Requirements:
- Maximum dimensions: 30 mm (length) × 15 mm (width) × 25 mm (thickness).
- Minimum dimensions: 1.5 mm (length) × 1.5 mm (width) × 2 mm (thickness).
- If the tissue exceeds the maximum size, trim it to the specified dimensions before embedding. Cutting frozen embedded tissues risks irregular fracturing.
2) Post-Collection Handling:
- Immediately blot the surface of fresh tissues with clean, lint-free paper to remove residual fluids. Avoid moisture retention, as ice crystal formation during freezing can compromise sectioning quality.
- Perform all procedures on ice to maintain a low-temperature environment and prevent metabolite degradation.
Can Pre-Embedded Samples Be Submitted?
Yes. We highly recommend using CMC (carboxymethyl cellulose) embedding medium, which minimizes signal interference and ensures sample integrity.
Embedding Protocol:
1) Pre-cool the embedding medium on ice, and label the mold to indicate the sectioning orientation.
2) Add a layer of embedding medium to the mold, then quickly place the tissue into it using pre-chilled forceps.
3) Cover the tissue completely with additional medium, adjusting its position to ensure alignment with the desired sectioning plane. Avoid air bubbles (gently remove any bubbles with a needle tip).
4) Freeze the mold immediately on dry ice or at -80°C until solidified. Note: Crushed dry ice ensures uniform cooling during embedding.
Can Clients Perform Their Own Sectioning?
Yes. Clients may opt to prepare their own sections.
Sectioning Guidelines:
- Thickness: 8–50 μm (12 μm recommended for human/animal tissues).
- Section Size: ≤ 65 mm × 40 mm (client-prepared) or ≤ 50 mm × 30 mm (company-prepared).
Procedure:
1) Equilibrate tissues at -20°C for 30 minutes before sectioning.
2) Mount the tissue onto a sample holder using CMC solution. Ensure the sectioning plane faces upward and remains horizontal.
3) Adjust the cryostat settings (temperature, thickness, anti-roll plate position) and cut sections onto pre-cooled ITO (indium tin oxide) glass slides.
Troubleshooting:
- Brittle sections: Increase the sample holder temperature.
- Soft sections: Decrease the temperature.
4) Transfer sections to ITO slides using a chilled brush. Gently press the slide against your hand to thaw and adhere the tissue. Evaporate residual moisture by rubbing the slide’s back.
5) Store slides at -80°C and ship on dry ice. Submit 3 ITO slides per sample for redundancy.
Cleanliness: Wipe the cryostat platform and anti-roll plate with ethanol between samples to prevent cross-contamination.
Can Fresh Samples Be Submitted Directly for Spatial Metabolomics?
Yes, but with precautions:
Animal Tissues: Flash-freeze samples on dry ice or liquid nitrogen. Wrap in aluminum foil and place in a centrifuge tube or cryobox. Use blunt forceps to reshape any deformations before freezing.
Plant Tissues: Trim to size, flash-freeze on dry ice (avoid liquid nitrogen), wrap in foil, and store in sealed containers.
Note: We will embed fresh samples prior to sectioning to mitigate risks of deformation during shipping.
Sample Shipping Protocol
1) Packaging:
- Wrap embedded tissue blocks or cryoboxes in aluminum foil and label clearly.
- Place small samples in 50 mL centrifuge tubes. For larger samples, use cryoboxes with compartments for multiple samples.
- Avoid direct contact between samples and container walls to prevent adhesion.
2) Dry Ice Shipping:
- Bury containers completely in crushed dry ice (≥4 kg per day of transit).
- Use thick foam boxes for insulation.
Why Choose MetwareBio for Spatial Metabolomics?
As a leader in spatial metabolomics services, MetwareBio offers end-to-end solutions, including:
- Expert Sample Handling: Optimized protocols for embedding, sectioning, and matrix coating to preserve metabolite integrity.
- High-Resolution Imaging: MALDI-MSI technology with customizable resolutions (5–100 μm).
- Advanced Data Analysis: Integration with SCiLS Lab for spatial visualization, pathway mapping, and multi-omics correlation.
- Cross-Disciplinary Support: Tailored solutions for medical, agricultural, and ecological research.
