Development of the Single-Cell MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight) Mass-Spectroscopic Assay

MALDI-TOF mass spectrometry was used to detect intracellular molecules from a single intact cell on monolayers of other cells. Intracellular molecules, e.g., histamine, were gradually increased in a mouse bone marrow-derived mast cell by a maturation process. A single cell was captured by a microsuction pipette, and the mass spectra of intracellular histamine were measured directly. Finally, the time course of the intracellular molecular contents and the maturation stage from a single cell were estimated.