Ultra-High-Throughput and Low-Volume Analysis of Intact Proteins with LAP-MALDI MS

Area of Science:

• Analytical Chemistry
• Biochemistry
• Mass Spectrometry

Background:

• High-throughput (HTP) mass spectrometry (MS) is crucial for analyzing increasing sample volumes.
• Existing HTP MS techniques often require large sample volumes (20-50 μL).
• A need exists for HTP MS methods with reduced sample consumption.

Purpose of the Study:

• To present liquid atmospheric pressure-matrix-assisted laser desorption/ionization (LAP-MALDI) MS as an alternative for ultra-high-throughput protein analysis.
• To demonstrate the capability of LAP-MALDI MS for analyzing femtomole quantities of protein in minimal volumes.
• To evaluate the achievable analysis rates and sensitivity of LAP-MALDI MS.

Main Methods:

• Utilized liquid atmospheric pressure-matrix-assisted laser desorption/ionization (LAP-MALDI) MS.
• Employed a high-speed XY-stage actuator to move a 384-well microtiter sample plate.
• Analyzed protein mixture and individual protein solutions at varying concentrations.

Main Results:

• Achieved sample acquisition rates of up to 10 samples per second.
• Demonstrated analysis of protein mixtures at concentrations ≤2 μM and individual proteins at ≤0.2 μM.
• Required only femtomole quantities of protein in 0.5 μL droplets.

Conclusions:

• LAP-MALDI MS is a promising platform for ultra-high-throughput multiplexed protein analysis.
• The method significantly reduces sample volume requirements compared to other HTP MS techniques.
• High analysis speeds and sensitivity make LAP-MALDI MS suitable for demanding proteomic studies.