DETERMINATION OF INSULIN CONTENT IN PANCREATIC BETA-CELL LINE MIN6 CELLS BY MATRIX-ASSISTED LASER-DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY

The insulin content in mouse insulinoma MIN6 cells was determined usin g matrix-assisted laser desorption ionization (MALDI) time-of-flight m ass spectrometry (TOF/MS), A mass spectrum of cellular insulin was obt ained with a cell burst of MIN6 by hypotonic water. Signal intensities of intracellular insulin were proportional to the number of MIN6 cell s. The present method was applied to the determination of intracellula r insulin content of MIN6 before and after glucose stimulation.