There are described a new type of sample holder for performing analyses of biological samples with mass spectrometry in MALDI mode, the process for its production and some protocols for the use of the sample holder in said technique. The sample holder, in its simplest embodiment (10), consists of a support (11) on a face (12) of which there is at least one porous deposit (13) consisting of nanoparticles of an oxide of a Group 4 metal.

The invention proposes preparing biological samples for spectrometry which contain cell structures and/or whole cells of human or animal origin (e.g. thin human and animal tissue sections) or prokaryotes (e.g. microorganisms), and which require constant relative humidity, in a temperature-controlled gas volume whose humidity is determined by a saturated substance solution, for example a suitable salt solution. The invention exploits a physico-chemical phenomenon called “deliquescence”, which manifests itself by keeping the relative humidity above the saturated substance solution constant with a high degree of precision when a specified temperature is maintained. Pure succinic acid exhibits deliquescence at approx. 99% relative humidity, for example. Since an enormous variety of deliquescent salts and other suitable substances are available, it is possible to find the suitable substance for almost any desired relative humidity, with adjustment of the temperature, where necessary.

A surface-assisted laser desorption/ionization method according to an aspect includes: a first process of preparing a sample support (2) having a substrate (21) in which a plurality of through-holes (S) passing from one surface (21a) thereof to the other surface (21b) thereof are provided and a conductive layer (23) that covers at least the one surface (21a); a second process of placing a sample (10) on a sample stage (1) and arranging the sample support (2) on the sample (10) such that the other surface (21b) faces the sample (10); and a third process of applying a laser beam (L) to the one surface (21a) and ionizing the sample (10) moved from the other surface (21b) side to the one surface (21a) side via the through-holes (S) due to a capillary phenomenon.

A method and apparatus for monitoring and/or controlling the extent of denaturation and/or bond cleavages of proteins on any surface (e.g., biological tissues, biofilms, etc.). In one embodiment, a low power laser (e.g., a 5 mW, 362 nm diode laser) is directed through a biological sample to a photodetector. The sample is heated by a set of radiant heaters to between about 220° C. and about 250° C. in a time period of between 10 seconds to 60 seconds. The baseline transmissivity of the sample is monitored continuously throughout treatment of the biological sample via continuous monitoring of the signal voltage detected at the photodetector. Upon detection of increase in relative transmissivity in the biological sample, the heating treatment is concluded and the biological sample is removed for in situ protein identification as part of an imaging MALDI-MS measurement.

Humidification systems and methods to introduce water vapor to a laser-ablated sample prior to introduction to an ICP torch are described. A system embodiment includes, but is not limited to, a water vapor generator configured to control production of a water vapor stream and to transfer the water vapor stream to at least one of a sample chamber of a laser ablation device or a mixing chamber in fluid communication with the laser ablation device, wherein the mixing chamber is configured to receive a laser-ablated sample from the laser ablation device and direct the laser-ablated sample to an inductively coupled plasma torch.

A method for processing samples is presented, said method useful for, among other uses, analysis of components of a sample including lipids, said method further useful for identification of microorganisms, bulk extraction of lipids, detecting infections and other diseases, and other purposes.

A mass spectrometry imaging system includes an ionization source located at a first location configured to produce ions from a surface of a sample at the first location; a mass spectrometer located at a second location configured to perform mass spectrometry analysis by analyzing the produced ions based on mass to charge ratio of the ions; and an ion transfer device configured to transfer the ions from the first location to the second location such that the ion transfer device includes a plurality of electrodes, the plurality of electrodes configured to be flexible or flexibly connected to each other, and the ion transfer device is configured to be flexible or re-configurable while transferring the ions.

A sample support body for ionization of a sample, including: a substrate having a first surface, a second surface on a side opposite to the first surface, and a plurality of through-holes opening on each of the first surface and the second surface; a conductive layer provided on the first surface; and a matrix crystal layer provided on at least one of the conductive layer and the second surface, in which the matrix crystal layer is formed of a plurality of matrix crystal grains so as to include a gap communicating the plurality of through-holes with an outside.

Disclosed herein include systems, devices, and methods for droplet deposition for mass spectrometry. In some embodiments, a microfluidic device comprising wells is reversibly sealed to a mass spectrometry surface and used to deposit contents of droplets (e.g., enzymes and substrates), or products thereof, onto the mass spectrometry surface. The contents of droplets can be analyzed by laser desorption/ionization to, for example, identify a substrate of an enzyme or an enzyme capable of catalyzing a substrate to a product.

Each of one or more unknown compounds are separated from a sample over a separation time period. Separated compounds are ionized, producing one or more compound precursor ions for each of the unknown compounds and a plurality of background precursor ions. A precursor ion mass spectrum is measured for the combined compound and background precursor ions at each time step of a plurality of time steps spread across the separation time period, producing a plurality of precursor ion mass spectra. One or more background precursor ions are selected from the plurality of precursor ion mass spectra that have a resolving power in a range below a threshold expected resolving power. A separation time is detected for an unknown compound when a decrease in an intensity measurement of the selected background precursor ions over a time period exceeds a threshold decrease in intensity with respect to time.