On-Valve μSFE-SFC-MS Enables Fast Analysis of Single Oocyte Lipidome

Area of Science:

• Reproductive Biology
• Analytical Chemistry
• Biochemistry

Background:

• Lipid regulation and remodeling are critical for ovarian follicle development and oocyte maturation.
• Single oocyte lipidome analysis is vital for enhancing assisted reproductive techniques (ART) and pregnancy success.
• Conventional lipid extraction methods are unsuitable for single-cell analysis due to time constraints and sample dilution.

Purpose of the Study:

• To develop a novel, rapid on-valve microflow supercritical fluid extraction and chromatography-mass spectrometry (μSFE-SFC-MS) method for single oocyte lipidomics.
• To analyze lipidomic profiles of single oocytes across different maturation stages.
• To identify specific lipid biomarkers for assessing oocyte maturation at the single-cell level.

Main Methods:

• Development of an on-valve microflow supercritical fluid extraction and chromatography-mass spectrometry (μSFE-SFC-MS) workflow.
• Online extraction of lipids from intact single oocytes using supercritical carbon dioxide.
• Separation, ionization, and annotation of lipids using a C18 capillary column and mass spectrometry.

Main Results:

• The μSFE-SFC-MS method reduced sample analysis time to 15 minutes per oocyte, a significant improvement over conventional methods (approx. 2 hours).
• Analysis of 276 distinct lipid species from individual oocytes was achieved.
• Distinct lipidomic remodeling, including shifts from phospholipids to sphingomyelins and glycerides, was observed during oocyte maturation.

Conclusions:

• The developed μSFE-SFC-MS method provides a fast, high-coverage approach for single oocyte lipidomic analysis.
• Specific lipid species can serve as reliable criteria for determining oocyte maturation status at the single-cell level.
• This workflow is applicable to other single-cell and trace sample lipidomic studies.