Abstract: Apparatus and methods are described for preparing samples for examination by cryo-electron microscopy. Molecules of interest, such as protein molecules in a solution, are electrosprayed and converted to singly-charged gas-phase ions. Particular conformation(s) of the protein ions are selected by using an ion mobility filter and deposited onto a cryo-EM grid at sub-eV kinetic energy for the purpose of preserving the molecule's higher order structure.

Abstract: Apparatuses and methods are described for determining properties of ions travelling through a gas under the influence of an electric field. The apparatuses and methods can be understood to provide measurements of the electrical mobility of ions as useful for determining the electrical mobility constant Ko of electrosprayed substances, such as proteins. The apparatuses and methods relate to the scientific discipline of ion mobility spectrometry. Modules connected to ion mobility spectrometers provide stress to substances for the purpose of investigating, for example, the thermal stability of proteins. One form of the technology includes a tubular spectrometer body having an electrically conductive inner wall; a rod positioned along the longitudinal center of the body and electrodes positioned on, but electrically isolated from, the inner wall, where the ratio of the radius of the tubular spectrometer body to the ratio of the radius of the rod is at least 20.

Abstract: Apparatuses and methods are described for determining properties of ions travelling through a gas under the influence of an electric field. The apparatuses and methods can be understood to provide measurements of the electrical mobility of ions as useful for determining the electrical mobility constant Ko of electrosprayed substances, such as proteins. The apparatuses and methods relate to the scientific discipline of ion mobility spectrometry. Modules connected to ion mobility spectrometers provide stress to substances for the purpose of investigating, for example, the thermal stability of proteins. One form of the technology includes a tubular spectrometer body having an electrically conductive inner wall; a rod positioned along the longitudinal center of the body and electrodes positioned on, but electrically isolated from, the inner wall, where the ratio of the radius of the tubular spectrometer body to the ratio of the radius of the rod is at least 20.

Abstract: Apparatuses and methods are described for determining properties of ions travelling through a gas under the influence of an electric field. The apparatuses and methods can be understood to provide measurements of the electrical mobility of ions as useful for determining the electrical mobility constant Ko of electrosprayed substances, such as proteins. The apparatuses and methods relate to the scientific discipline of ion mobility spectrometry. Modules connected to ion mobility spectrometers provide stress to substances for the purpose of investigating, for example, the thermal stability of proteins. One form of the technology includes a tubular spectrometer body having an electrically conductive inner wall; a rod positioned along the longitudinal center of the body and electrodes positioned on, but electrically isolated from, the inner wall, where the ratio of the radius of the tubular spectrometer body to the radius of the rod is at least 20.

Abstract: Methods of ion mobility spectrometry are provided in which a sample material is modified by exposing the sample material to physical stress to produce a modified material, ions are generated from the modified material to produce generated ions, the generated ions are separated to produce separated ions and the separated ions are detected. The modified material is delivered to an electrospray generator and are separated and detected. Embodiments of the invention modify the ions after they are generated. After detection, the data is processed mathematically to produce processed data that is recognized by experts in the field of ion mobility spectrometry. Apparatuses are provided to carry out the methods.