Efficient sample preparation in immuno-matrix-assisted laser desorption/ionization mass spectrometry using acoustic...

Area of Science:

• Biotechnology
• Analytical Chemistry
• Biophysics

Background:

• Automating laboratory assays is crucial for efficiency and reproducibility.
• Immuno-matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) requires effective sample preparation for sensitive detection.
• Traditional bead-based assays can be labor-intensive and time-consuming.

Purpose of the Study:

• To develop and validate a novel acoustic trapping method for automated sample preparation in immuno-MALDI-MS.
• To demonstrate the efficiency and speed of acoustic trapping for analyte enrichment.
• To showcase the versatility of the method using a model peptide hormone.

Main Methods:

• Utilizing acoustic trapping in microfluidic capillaries (200 × 2000 μm²) to capture antibody-coated beads (2.8 μm).
• Employing an aspirate/dispense format for automated assay steps, including washing.
• Testing the method with an antibody against Angiotensin I (Ang I) spiked in plasma samples.

Main Results:

• Acoustic trapping enabled highly efficient binding and washing, completely removing detergents.
• Sample processing times were significantly reduced to 5-10 minutes.
• The method demonstrated efficient enrichment of Angiotensin I at 400 pM in plasma.

Conclusions:

• Acoustic trapping offers a rapid and automated solution for sample preparation in immuno-MALDI-MS.
• This technique significantly enhances assay efficiency and reduces processing time.
• The method is versatile and effective for enriching peptide hormones from complex biological matrices like plasma.