Abstract: The present invention is directed to probes and methods for the imaging of specimens such as tissue samples or other biological specimens or arrays using mass spectrometry (MS). In one aspect, there is provided a method for analysing a specimen comprising the steps of contacting the specimen with probe molecules each of which includes one or more mass tags coupled to each probe molecule via a first cleavable linker, contacting the specimen with a Matrix-assisted Laser Desorption lonisation (MALDI) matrix or similar material, irradiating a portion of the specimen with a laser beam to release ions from the specimen, selecting released ions with mass-to-charge ratios corresponding to the mass tags or derivatives of the mass tags, and recording the amount and type of ions selected together with the location of the portion of the specimen. The irradiation, selection and recording steps are then repeated on a different portion of the specimen.

Abstract: The invention describes compounds useful for labelling molecules of interest (i.e. analytes), particularly biomolecules such as peptides, proteins, oligonucleotides and nucleic acids, and also methods for analysing, detecting and/or isolating these labelled molecules using mass spectrometry. The compound in one aspect is a mass marker for labelling of an analyte detectable by mass spectrometry such as neutral loss mass spectroscopy, in which the mass marker comprises a neutral loss mass modifier linked via a first collision cleavable linker to a reactive group having reactive functionality for attachment to the analyte. The neutral loss mass modifier upon cleavage from the analyte during mass spectroscopy is uncharged.

Abstract: Provided is a method for characterizing an analyte by matrix assisted laser desorption ionization (MALDI) mass spectrometry, which method comprises: (a) labelling the analyte with a light-absorbing label that absorbs light at a pre-determined frequency, to form a labelled analyte; (b) embedding the labelled analyte in a matrix formed from at least one compound that absorbs light, to form an embedded labelled analyte; (c) desorbing the embedded labelled analyte by exposing it to light having the pre-determined frequency, to form a desorbed analyte; and (d) detecting the desorbed analyte by mass spectrometry to characterize the analyte.