Objective:

To develop a protocol for extracting metabolites and lipids from a single dried blood spot for dual omics analyses.

Approach:

• Extraction Method: A modified Folch extraction is used to separate metabolites and lipids from a 10 µL dried blood spot using a 2:1 mixture of chloroform and methanol, followed by sonication, water addition, and centrifugation.
• Analysis Technique: The extracts are analyzed using reversed-phase liquid chromatography-tandem mass spectrometry, specifically with a Q Exactive Orbitrap mass spectrometer.
• Data Processing: Two open-source tools, Mzmine and LipidMatch, are utilized for metabolite and lipid data processing, respectively.

Key Findings:

• The method allows for the extraction of both metabolites and lipids from a single dried blood spot.
• Results are semiquantitative, enabling comparison of peak heights or areas between groups.
• The protocol includes controls to assess contamination, analytical variation, and instrument performance.

Limitations:

• Absolute concentrations cannot be determined without additional standards and method validation.
• Variability in lipid feature identification was observed between extraction trials.

Conclusion:

This protocol provides a streamlined approach for dual omics analyses from a single dried blood spot, facilitating research in small sample contexts.

Sources:

• STAR Protocols