116 results about "Laser desorption ionization mass spectrometry" patented technology

Zwitterionic polymers bearing positive and negative charges are readily prepared from easily accessible precursors. The polymers show enhanced binding affinities for analytes under high salt conditions, compared to similar polymers bearing a charge of a single polarity. The polymers can also include an energy absorbing moiety for use in matrix assisted laser desorption / ionization mass spectrometry. The polymer can also include a photo-curable group, which can be used to form cross-links within the bulk polymer or between the polymer and a surface functionalized with a polymerizable moiety. The polymers are incorporated into devices of use for the analysis, capture, separation, or purification of an analyte. In an exemplary embodiment, the invention provides a substrate coated with a polymer of the invention, the substrate being adapted for use as a probe for a mass spectrometer.

A new ionization source named Surface Activated Chemical Ionization (SACI) has been discovered and used to improve the sensitivity of the mass spectrometer. According to this invention the ionization chamber of a mass spectrometer is heated and contains a physical new surface to improve the ionization process. The analyte neutral molecules that are present in gas phase are ionized on this surface. The surface can be made of various materials and may also chemically modified so to bind different molecules. This new ionization source is able to generate ions with high molecular weight and low charge, an essential new key feature of the invention so to improve sensitivity and reduce noise. The new device can be especially used for the analysis of proteins, peptides and other macromolecules. The new invention overcomes some of the well known and critical limitations of the Electrospray (ESI) and Matrix Assisted Laser Desorption Ionization (MALDI) mass spectrometric techniques.

The present invention relates to non contact, vision (imaging device / camera) guided, vision-enabled, solenoid valve liquid dispensing systems and methods of using same for automation of complex laboratory workflows and especially useful for a variety of biomedical and other applications including automated front-end sample preparation for matrix assisted laser desorption / ionization (MALDI) mass spectrometry analysis.

Polyurethane polymers bearing multiple reactive groups are readily prepared from easily accessible precursors. The reactive groups of the polymers are then derivatized with binding functionalities for analytes, energy absorbing molecules for matrix assisted laser desorption / ionization mass spectrometry, fluorescent moieties and the like. The reactive groups can also be converted to different reactive groups having a desired avidity or specificity for a selected reaction partner. The polymers are incorporated into devices of use for the analysis, capture, separation, or purification of an analyte. In an exemplary embodiment, the invention provides a substrate coated with a polymer of the invention, the substrate being adapted for use as a probe for a mass spectrometer.

The present invention relates to the use of post source decay (PSD) or collision induced dissociation (CID) direct tissue (DT) MALDI-TOF or DT-MALDI-TOF-TOF mass spectrographic identification of biological molecules in a tissue or cellular sample without the need for further protein extraction. This method provides for studying cells or tissues by direct tissue MALDI (DT-MALDI), thereby substituting in situ protein release for further protein extraction. Mass / intensity data was processed with Mascot© software interrogation of the NCBI database. These results are proof of principle that DT-MALDI, combined with bioinformatics, can directly identify proteins in cells and tissues from their mass spectra.

A novel Matrix-Assisted Laser Desorption / Ionization Mass Spectrometry (MALDI-MS) sample support plate is described. The plate comprises a top sample presentation surface and a lower surface, wherein the top sample presentation surface comprises at least one aperture for receiving a sample. The aperture extends through and between the top sample presentation surface and the bottom surface, and contains a porous material that retains and concentrates at the target spot analyte and matrix molecules contained in the sample on the surface of the aperture. Methods for making and using the sample support plate in conventional and automated MALDI-MS are also described.

The present invention relates to a probe for the analysis of one or more analytes, particularly proteins or compounds capable of binding or otherwise interacting therewith, by laser desorption / ionization mass spectrometry, more particularly MALDI MS. It also relates to a protein microarray, a method of producing a protein microarray and a method of analyzing a protein microarray. The probe comprises a support having an electroconductive target surface thereon characterized in that the target surface comprises a micro array having a plurality of discrete target areas presenting one or more analyte capture moieties. Each discrete target area has an area of less than 1000 μm2, more preferably still less than 500 μm2, and more preferably still less than 100 μm2.

Embodiments of the present invention relate to the identification of proteins using laser desorption ionization mass spectrometry, the identification of source organisms comprising the identified proteins and a computer readable storage medium storing instructions that, when executed by a computer cause the computer to perform a method for the identification of proteins using mass spectra generated through the application of laser desorption ionization mass spectrometry of the proteins.

The present invention relates to small sample spots for MALDI targets and methods for producing the same. The sample spots are composed of a layer of matrix material and a layer of analyte. In some instances, the samples spots have diameters of no more than 50 micrometers or even smaller. The sample spots are deposited onto a MALDI target substrate using ultrasonic deposition from a nozzle.

A mass spectrometric imaging method includes the steps of: forcing sequentially generated charge-laden liquid drops to move towards a receiving unit of a mass spectrometer along a traveling path; scanning a sample with a laser beam which has an irradiation energy sufficient to cause analytes contained in the sample to be desorbed to fly along a plurality of flying paths respectively; and positioning the sample relative to the laser beam to render the plurality of flying paths intersecting the traveling path so as to permit a plurality of the analytes respectively along the plurality of flying paths to be occluded in a plurality of the charge-laden liquid drops respectively to thereby form a plurality of corresponding ionized analytes.

Arginine-containing cysteine-modifying compounds useful for MALDI-MS analysis of proteins are provided. These compounds termed isotope-coded ionization enhancement reagents (ICIER) can provide ionization enhancement in MALDI-MS, relative quantitation, and additional database searching constraints at the same time without any extra sample manipulation. More specifically, ICIER increase the ionization efficiency of cysteine-containing peptides by attachment of a guanidino functional group. ICIER also increase the overall hydrophilicity of these peptides due to the hydrophilic nature of ICIER and thus increase the percentage of recovery of these peptides during sample handling and processing such as in-gel digestion or liquid chromatography. Finally, a combination of both light and heavy ICIER provides an accurate way to obtain relative quantitation of proteins by MALDI-MS and additional database searching constraints (number of cysteine residues in every single peptide peak) to increase the confidence of protein identification by peptide mass mapping.

A self-assembled engineered lattice of nanometer-scale silica particles, or other suitable particles generally resembling regularly-sized spheres, is configured in a separation bed for electrophoresis, isoelectric focusing, chromatography, or other voltage-induced separation of analytes. After separation, the analytes are immobilized on the separation bed and then ionized using matrix-assisted laser desorption / ionization (MALDI) for use with a mass spectrometer. The nanoparticles can be coated with polymers that activate to immobilize the analytes or assist with MALDI. The separation can occur in two dimensions.

A method of analyzing a polynucleotide using matrix assisted laser desorption / ionization mass spectrometry (MALDI-MS) is described. The method includes obtaining the polynucleotide bound to a substrate via a linker moiety having a triaryl methyl linker group. The polynucleotide bound to the substrate is then contacted with a matrix material and analyzed by MALDI-MS. During the MALDI-MS analysis, laser radiation is directed at the matrix material, thereby exciting the matrix material and causing cleavage of the linker moiety. Ions generated as a result of this excitation and cleavage process are then analyzed to provide information about the polynucleotide.

The invention provides a simple, rapid and cost-effective metal oxide-assisted laser desorption / ionization mass spectrometry (MOALDI MS) without the addition of light-absorbing organic-matrix, comprising the use of (a) an inorganic metal oxide with light absorbing capability as an assisting material to render desorption / ionization of samples in laser desorption / ionization mass spectrometry and (b) a citric acid buffer as the proton source for enhancing the ionization efficiency for analytes. Metal oxide assisting materials is not only restricted to the uses of films. Metal oxide nanoparticles are also suitable to be used as the assisting materials. Low matrix background, stable surface feature, homogeneous sample deposition, and wide detectable mass range are the merits of MOALDI MS.

A plate for laser desorption ionization mass spectrometry comprising an electrically conductive substrate (1) covered with an array of spots of sintered nanoparticles (2) acting as a highly efficient sorbing phase, a very sensitive photo-reactive phase and an ionization device when covered by an organic matrix or by a hole conductor or electron donor instead of an organic matrix.

The invention discloses application of naphthylethylenediamine inorganic acid salt or naphthylethylenediamine organic acid salt as a matrix in MALDI MS (matrix-assisted laser desorption / ionization mass spectrometry). In the application, the MALDI MS is MALDI-TOF MS (matrix-assisted laser desorption / ionization - time-of-flight mass spectrometry); the naphthylethylenediamine inorganic acid salt is naphthylethylenediamine hydrochloride, naphthylethylenediamine nitrate, naphthylethylenediamine phosphate or naphthylethylenediamine sulfate; and the naphthylethylenediamine organic acid salt is naphthylethylenediamine trifluoroacetate, naphthylethylenediamine acetate, naphthylethylenediamine formate, naphthylethylenediamine citrate or naphthylethylenediamine oxalate. The invention technically overcomes the defect that small-molecule samples cannot be effectively analyzed because serious matrix background interference is apt to be caused in a low molecular weight zone when organic small-molecule matrices are commonly used. The matrix used by the invention is not required to be added with ionizing reagent and the requirements on sample treatment are reduced; and since background interference hardly exists within a testing range (m / z: 0-1000), kinds of complex mixed systems can also be analyzed by using the matrix.

A laser optical bench for use with a laser desorption / ionization mass spectrometer. The laser optical bench includes a laser for producing light, a focusing structure that receives light from the laser and focuses predominantly in a single plane, an attenuator that receives light from the focusing structure, beam steering structure for directing light from the attenuator from the target; and a final focusing element for focusing light from the beam steering structure on the target. Further focusing elements may be included for further focusing and dispersing the light beam in different planes. Additionally, photodetectors or photodiodes may be included for energy measurement and sensing a lasing event.

A plate for matrix-assisted laser desorption ionization (MALDI) mass spectrometry comprising an electrically conductive substrate (1) covered with a light sensitive matrix (2), the matrix (2) comprising a light absorber, a charge carrier, a probe molecule and a photo-sensitizer (3) arranged to oxidise the probe molecule when irradiated with light (4).

Laser desorption / ionization tandem mass spectrometer instruments that include immediate post source collisional cooling are presented, as are analytical methods that employ such instruments to achieve increased sensitivity and ion yield. Also presented are laser desorption / ionization mass spectrometry methods that improve sensitivity and relative ion yield by combining affinity capture probes with matrices having low melting point energy absorbing molecules combined with alkali metal scavengers.

A method for diagnosing depression includes providing surface-enhanced laser desorption / ionisation mass spectrometric (SELDI-MS) data of a plurality of proteins, said data obtained from a patient and comprising a plurality of peak values, and analysing said peak values with an alternating decision tree comprising a set of tests of said data peaks values and associated prediction values, wherein said data is predictive of depression if a sum of the prediction values of said tree is greater than 1.0.

The invention discloses an application of tungsten disulfide in laser desorption ionization mass spectrometric detection. According to the invention, the tungsten disulfide is taken as a surface material for surface-assisted laser desorption ionization for mass spectrometric detection on small organic molecules. A tungsten disulfide suspension liquid is prepared firstly, and then subjected to ultrasonic oscillation for 5 minutes; 1 muL of the tungsten disulfide suspension liquid is dripped on sample target points; 1 muL of the small organic molecule solution to be detected is dropwisely adding on the films formed by the dried the tungsten disulfide suspension liquid; mass spectrometry is conducted after the small organic molecule solution is dried. The application has the advantages as follows: the mass spectrometric detection method is convenient in operation and low in cost; the degree of dispersion of the tungsten disulfide in the solvent is good; the sample target points are uniform in distribution; the reproducibility and the universality are high; the ionization efficiency of the organic molecules is high; the tungsten disulfide can effectively inhibit reduction reactions of riboflavin during the laser desorption ionization process and has important significance for researching the metabolic process of riboflavin in human bodies.

The invention discloses a core-shell type gold / mesoporous silicon carbon composite nanometer material, a preparation method and application. The core-shell type gold / mesoporous silicon carbon composite nanometer material is characterized in that a core-shell type nanometer material is synthesized with gold nanometer particles as an inner core and ordered mesoporous structure silicon dioxide surface active agent as a shell, and a core-shell type nanometer material with gold nanometer particles as an inner core and a mesoporous silicon carbon composite structure as a shell is prepared through in-situ carbonization of the surface active agent in the mesoporous silicon dioxide shell. The material has the advantages that the specific surface area is high, the pore volume is high, the material is wrapped by a uniform ordered mesoporous structure silicon carbon shell, and the thickness of the shell is controllable. The nanometer material mainly serves as a matrix of the surface auxiliary laser desorption ionization mass spectrometry, the background interference of a traditional organic matrix within the low-molecular-weight range can be avoided, and the efficient laser desorption ionization of compound to be measured is achieved.

The invention discloses application of naphthylhydrazine inorganic acid salt or naphthylhydrazine organic acid salt as a matrix in MALDI MS (matrix-assisted laser desorption / ionization mass spectrometry). The MALDI MS is MALDI-TOF MS (matrix-assisted laser desorption / ionization - time-of-flight mass spectrometry); the naphthylhydrazine inorganic acid salt is naphthylhydrazine hydrochloride, naphthylhydrazine nitrate, naphthylhydrazine phosphate or naphthylhydrazine sulfate; and the naphthylhydrazine organic acid salt is naphthylhydrazine trifluoroacetate, naphthylhydrazine acetate, naphthylhydrazine formate, naphthylhydrazine citrate or naphthylhydrazine oxalate; and hydrazine radicals on the naphthylhydrazine inorganic acid salt or naphthylhydrazine organic acid salt are all 1-substituted or 2-substituted. The application technically overcomes the defect that small-molecule samples cannot be effectively analyzed because serious matrix background interference is apt to be caused in a low molecular weight zone when organic small-molecule matrices are commonly used. The matrix used by the invention is not required to be added with ionizing reagent and the requirements on sample treatment are reduced; and since background interference hardly exists when m / z is smaller than 500, various complex mixed systems can also be analyzed by using the matrix.

The invention relates to a mass spectrum image super-resolution reconstruction method based on deep learning, and belongs to the image processing field. The mass spectrum image super-resolution reconstruction method based on deep learning includes the following steps: using a matrix-assisted laser desorption / ionization mass spectrometry imaging instrument to perform imaging on a biological sample,according to different m / z values, obtaining multiple mass spectrum images, obtaining multiple low resolution images through down-sampling, solving the morphological information of the acquired high / low resolution images and taking the morphological information as a training sample set, designing and training deep convolutional neural networks, according to the input training sample set, predicting the missing information in the low resolution images; during the test stage, by means of the prior knowledge obtained through networks, guiding reconstruction of the morphological information of the low resolution mass spectrum images; and reconstructing the morphological information into high resolution mass spectrum images by establishing a partial differential equation. The mass spectrum image super-resolution reconstruction method based on deep learning avoids the defect that a traditional technology improves the imaging quality by improving imaging equipment or by means of repeated sampling, can reduce the cost and the experimental cycle, and can breakthrough limitation of image resolution for a hardware system.

The invention provides a simple, rapid and cost-effective metal oxide-assisted laser desorption / ionization mass spectrometry (MOALDI MS) without the addition of light-absorbing organic-matrix, comprising the use of (a) an inorganic metal oxide with light absorbing capability as an assisting material to render desorption / ionization of samples in laser desorption / ionization mass spectrometry and (b) a citric acid buffer as the proton source for enhancing the iorization efficiency for analytes. Metal oxide assisting materials is not only restricted to the uses of films. Metal oxide nanoparticles are also suitable to be used as the assisting materials. Low matrix background, stable surface feature, homogeneous sample deposition, and wide detectable mass range are the merits of MOALDI MS.

The invention discloses a surface assistant laser desorption ionization mass spectrometry analysis method for improving desorption ionization efficiency of analyte by enriching the analyte to a metal nanocone array tip, and belongs to the technical field of detection. A metal membrane is applied to the surface of a silicon nanocone array in an evaporation manner, then surface plasma element conduction is carried out, photon energy is accumulated in tip positions, and thus a photon library is formed. As the surface is modified with fluoro-substitution alkyl sulfhydryl, a substrate has a large contact angle and a small rolling angle, then the friction of water droplets on the substrate is very small, analyte molecules of a solution are preferentially concentrated at the tips, and the utilization rate of laser energy can be further increased. Therefore, when the silicon nanocone array covered by the metal membrane modified with the fluoro-substitution alkyl sulfhydryl is used as substrate detection analyte molecules, the laser energy can be sufficiently absorbed and effectively utilized, furthermore the desorption ionization efficiency of the analyte molecules can be improved, and the method is applicable to various types of molecules.

The invention relates to a method for separating, enriching and identifying macromolecular weight protein, belonging to the field of biochemical analysis. In the invention, a mixed gel of low-melting point agarose and polyacrylamide is used as an electrophoresis supporting medium, and an analysis path of gel slab electrophoresis combined with efficient liquid-phase chromatography - electrical spraying mass spectrum identification and another analysis path of solid-phase gradient pH dry adhesive tape isoelectro-focusing combined with gel slab electrophoresis separation - matrix auxiliary laser desorption ionization mass spectrum identification are collectively used to separate and identify the macromolecular weight protein. The gel provided by the invention has the advantages of big aperture, high mechanical strength, high resolution ratio, good repeatability and good mass spectrum compatibility; the macromolecular weight separation scope can be adjusted based on different component proportions; and protein with the molecular weight interval above 100kDa can be selectively separated with repeatability RSD up to 7.6%, thereby obviously improving the identification ratio. The method is an effective tool for separating the macromolecular weight protein, which can be applied to proteomics study field.

An object of the present invention is to provide a sample substrate for laser desorption ionization mass spectrometry for LDI-MS which substrate enables mass spectrometric analysis of a sample correctly at high sensitivity without generating interference peaks upon irradiation of the sample to laser light and uniform application of the sample onto a base. Another object of the invention is to provide a mass spectrometer (device) employing the sample substrate.In the sample substrate for laser desorption ionization mass spectrometry, the sample substrate is formed of a base and carbon nanowalls having wall surfaces onto which a sample to undergo mass spectrometry is applied, wherein the carbon nanowalls are formed on the base so as to stand on the base. The surfaces of carbon nanowalls serve as an ionization medium and hydrophilized. By use of the sample substrate, mass spectrometry of a sample having a wide range (high to low) molecular weight can be reliably performed at high precision and sensitivity.