Methods for identifying microorganisms using mass spectrometry

A method of identifying microorganisms from a blood sample, comprising: (a) obtaining a blood sample which is known to contain or may contain microorganisms; (B) lysing cells and selectively solubilize microorganism in said blood sample with a lysis solution to produce a lysed sample, lysis solution having a pH of 8 to 13; (C) placing a layer of said lysed sample on a damper bed density having a homogeneous density of 1.025 to 1.120 g / ml in a container and centrifuge bowl for separating said microorganisms from other components of said lysed sample, microorganisms that cross said bed cushion density to form a pellet of said microorganisms in the bottom of said vessel; (D) examining said sediment of said microorganisms by mass spectrometry to acquire a mass spectrum of said microorganisms: and (e) identifying said microorganisms in said sediment isolated sample by comparing the mass spectrum measured mass spectra of reference and / or known or anticipated cellular components masses known microorganisms, wherein said microorganisms are identified at family, genus level, the level of species and / or strain level.