High-throughput (HTP) mass spectrometry (MS) is a rapidly
growing
field, with many techniques evolving to accommodate ever increasing
sample analysis rates. Many of these techniques, such as AEMS and
IR-MALDESI MS, require volumes of at least 20–50 μL for
analysis. Here, liquid atmospheric pressure-matrix-assisted laser
desorption/ionization (LAP-MALDI) MS is presented as an alternative
for ultra-high-throughput analysis of proteins requiring only femtomole
quantities of protein in 0.5 μL droplets. By moving a 384-well
microtiter sample plate with a high-speed XY-stage actuator, sample
acquisition rates of up to 10 samples per second have been achieved
at a data acquisition rate of 200 spectra per scan. It is shown that
protein mixture solutions with concentrations of ≤2 μM
can be analyzed at this speed, while individual protein solutions
can be analyzed at concentrations of ≤0.2 μM. Thus, LAP-MALDI
MS provides a promising platform for multiplexed HTP protein analysis.