Method of Scanning a Sample Plate Surface Mask in an Area Adjacent to a Conductive Area Using Matrix-Assisted Laser Desorption and Ionization Mass Spectrometry

Abstract

A method of scanning a sample plate surface mask in an area adjacent to a conductive area using mass spectrometry is disclosed. The method comprises the steps of providing a sample plate including a mask applied with a rough surface to the electrically conductive surface to produce a sample site comprising a central portion formed from the electrically conductive surface and a marginal portion of the mask, preparing an analyte comprising mixing a biomolecule with an organic solvent, an aqueous solution, and a matrix selected from the group of α-cyano-4-hydroxycinnamic acid and 3,5-dimethoxy-4-hydroxycinnamic acid; applying the analyte to the sample site; forming at least one crystal of the analyte in an area on the mask adjacent to the conductive area, and scanning the area on the mask adjacent to the conductive area with a laser beam.

What is claimed is: 
     
         1 . A method of applying a specimen to sample plate surface mask in an area adjacent to a conductive area comprising the steps of:
 providing a sample plate including a mask applied with a rough surface to an electrically conductive surface to produce a sample site comprising a central portion formed from the electrically conductive surface and a marginal portion of the mask;   providing a liquid chromatography system for preparing a specimen comprising eluting a biomolecule with an organic solvent, an aqueous solution, and a matrix and applying the specimen;   moving the sample plate cooperatively with the liquid chromatography system; and   applying the specimen to the sample site.   
     
     
         2 . The method of  claim 1  wherein the matrix is selected from the group consisting of α-cyano-4-hydroxycinnamic acid and 3,5-dimethoxy-4-hydroxycinnamic acid. 
     
     
         3 . The method of  claim 1 , wherein the step of applying the specimen further comprises the step of applying the specimen at a rate of at least 1 μl per 1 mm. 
     
     
         4 . The method of  claim 1 , wherein the step of applying the specimen further comprises the step of applying the specimen within at least 0.2 mm of the periphery of the electrically conductive surface on the mask. 
     
     
         5 . The method of  claim 1 , wherein the step of providing a liquid chromatography system for preparing a specimen comprising eluting a biomolecule, further comprises eluting a biomolecule selected from the group consisting of oligonucleotides, DNA, RNA, peptide, polypeptide, oligopeptide, protein, glycoprotein, lipoprotein, carbohydrate, monosaccharide, disaccharide, polysaccharide, and combinations thereof.