Self-aliquoting microarray plates for accurate quantitative matrix-assisted laser desorption/ionization mass...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Mass Spectrometry

Background:

• Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a rapid analytical technique but faces challenges in quantitative applications due to sample inhomogeneity.
• Factors contributing to poor quantitation include inhomogeneous analyte/matrix co-crystallization and low replicate numbers.

Purpose of the Study:

• To present a novel MALDI sample target designed to overcome the limitations of quantitative MALDI-MS.
• To improve the accuracy and reproducibility of quantitative MALDI-MS through automated sample deposition.

Main Methods:

• Development and utilization of a microarray for mass spectrometry (MAMS) platform with hydrophilic reservoirs for automated sample deposition.
• Sample deposition involves dragging droplets with a metal slider, leveraging hydrophilic/hydrophobic interactions for rapid, homogeneous aliquoting into 10 nL spots.
• Evaluation of the sample targets using standard peptides and α-cyano-4-hdydroxycinnamic acid as a matrix.

Main Results:

• The novel MAMS target allows for the rapid deposition of up to 40 replicates from a few microliters of sample within seconds.
• Homogeneous and immediate drying of analyte droplets ensures consistent sample preparation for MALDI-MS analysis.
• Achieved coefficients of determination (r(2)) greater than 0.99 for standard peptides (angiotensin II and [Glu(1)]-fibrinopeptide B) without internal standards.

Conclusions:

• The developed MALDI sample target significantly enhances the suitability of MALDI-MS for quantitative analysis.
• The MAMS technology provides a robust platform for high-throughput, reproducible, and accurate quantitative measurements.
• This approach offers a promising solution for precise peptide quantification in various analytical applications.