High-Throughput Nano-DESI Mass Spectrometry Imaging of Biological Tissues Using an Integrated Microfluidic Probe.

Area of Science:

• Analytical Chemistry
• Biotechnology
• Mass Spectrometry Imaging

Background:

• Nanospray desorption electrospray mass spectrometry imaging (nano-DESI MSI) is a powerful technique for quantitative molecular mapping in biological samples.
• Previous integrated microfluidic probes (iMFP) for nano-DESI MSI offered potential but required further optimization for high-throughput applications.

Purpose of the Study:

• To develop an improved integrated microfluidic probe (iMFP) design for high-throughput nano-DESI MSI of tissue sections.
• To evaluate the impact of increased scan rates on imaging performance, including sensitivity, molecular coverage, and spatial resolution.

Main Methods:

• Redesigned the iMFP by increasing channel dimensions and optimizing spray voltage and solvent flow rate for stable operation at varying scan rates.
• Assessed imaging quality using a novel quantitative metric to evaluate ion image data at different scan rates.
• Applied the improved iMFP to image mouse uterine and brain tissue sections at accelerated scan rates.

Main Results:

• Achieved stable iMFP operation at both low and high scan rates without significant degradation in sensitivity, molecular coverage, or spatial resolution.
• Demonstrated a 10-15-fold improvement in experimental throughput, imaging mouse uterine tissue in 9.5 minutes and mouse brain tissue in 21.7 minutes.
• Validated that the quality of nano-DESI MSI data remains high even with increased scan rates, as confirmed by the quantitative metric.

Conclusions:

• The improved iMFP design enables high-throughput nano-DESI MSI of biological tissues.
• This advancement significantly accelerates tissue mapping efforts, making molecular profiling more efficient.
• The developed methodology maintains data integrity and quality at increased speeds, paving the way for faster biological discovery.