Single cell analysis is performed by mass spectrometry on plant and animal cells at atmospheric pressure by using a sharpened optical fiber to sample the cells for laser ablation electrospray ionization (LAESI) mass spectrometry.
Shrestha, B., Vertes, A. Direct Analysis of Single Cells by Mass Spectrometry at Atmospheric Pressure. J. Vis. Exp. (43), e2144, doi:10.3791/2144 (2010).