Monolithic Silica Microbands Enable Thin-Layer Chromatography Analysis of Single Cells

Area of Science:

• Analytical Chemistry
• Microfluidics
• Biotechnology

Background:

• Analyzing single cells requires ultra-sensitive techniques due to minute sample volumes.
• Existing methods often lack the resolution or throughput for single-cell analysis.
• Picoliter-scale analysis is crucial for understanding cellular heterogeneity.

Purpose of the Study:

• To develop a picoliter thin-layer chromatography (pTLC) platform for analyzing extremely miniature specimens, including single cells.
• To demonstrate the separation and detection capabilities of pTLC for picoliter-scale samples.
• To validate pTLC for analyzing the contents of single mammalian cells.

Main Methods:

• Fabrication of pTLC chips using sol-gel chemistry and microfabrication, creating microscale bands from porous monolithic silica.
• Utilizing a piezoelectric microdispenser to introduce picoliter volumes of fluorescent compounds onto microbands.
• Adjusting macropore size (0.3–2.3 μm) to control separation resolution and analyte migration.
• Employing standard fluorescence microscopy for analyte detection.

Main Results:

• Successful separation of model fluorescent compounds and biological lipids in picoliter volumes.
• Detection of attomole levels of analytes with a 0.3 μm macropore size.
• Achieved separation resolutions from 1.3 to 2.1 and theoretical plate numbers up to 357.
• Demonstrated pTLC analysis of single mammalian cells, detecting fluorescently labeled contents.

Conclusions:

• The developed pTLC platform enables high-resolution analysis of picoliter-scale samples, including single cells.
• pTLC offers attomole-level detection sensitivity and adjustable separation parameters.
• This technology holds significant potential for high-throughput parallel analyses in various fields requiring miniature specimen investigation.