Cel Many areas in biomedical sciences would benefit from development of novel methods for detailed two-dimensional molecular analysis of microscopic structures, such as single cells. High-resolution visualization by electron microscopic methods is well established but it gives no information on molecular composition. Secondary-ion mass spectrometric microscopy yields information on only metal ions and small molecules. Modern techniques matrix-assisted laser desorption ionisation (MALDI) and electrospray ionisation (ESI) offer sufficient sensitivity to large molecules but lack the necessary lateral resolution. We propose to develop two mutually complementary methods of two-dimensional analysis for objects of ~10 micrometers (µm) in size, with spatial resolution of down to ~ 0.1µm.In the first technique, we combine scanning electron microscopy with UV MALDI. A UV laser will generate a conventionally focused (100 µm) beam of under-threshold intensity, desorbing only neutrals. Ionisation is achieved by simultaneous pulsing (10 ns) of sharply focussed (=0.1 µm) keV electron beam that will be scanned between the shots across the cell covered with an appropriate matrix (including frozen water). The molecular ions formed in this MELADI technique (Matrix, Electrons, Laser Assisted Desorption Ionisation) will be analysed by the most sensitive up to date time-of-flight (TOF) mass spectrometry.The second imaging method, electromembrane ionisation (EMI) is analogous to ESI but is distinctly different in important aspects. It is based on a mass spectrometric ion source employing a polymer etched-track membrane with millions of cylindrical pores =0.1 µm diameter each. The average distance between the pores is currently 3 µm but can be made much smaller. The atmospheric side of the membrane is covered with a micrometer-thin layer of glycerol with a sample (a cell with a partially removed wall) pressed to the membrane. An electric field is applied across the membrane, inducing electrophoretic penetration of large molecules through the channels with subsequent emission of their glycerol-solvated molecular ions from the pores on the vacuum side. The research will be directed to achieve an ionic image on the vacuum side reflecting the molecular topography of the atmospheric side of the membrane.Simultaneously with MELADI and EMI development, fundamental studies are planned on the elementary processes in these techniques, aimed to increase the yield of intact molecular ions. These studies include both theoretical calculations and experimental spectroscopic determination of properties of neutral and ionic species involved.The test experiments in both ionisation techniques will first be done on peptides, with imaging of biological objects on the later stages. The application field of the developed techniques will be biomedical sciences. For example, differences can be investigated in expression of proteins playing important roles in the regulation of fundamental physiological processes within specific sub-cellular compartments. One can also compare the two-dimensional molecular composition of normal cells and cells derived from cancer patients to identify unique markers for tumor development. Program(-y) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Temat(-y) 4 - Life Sciences OPEN - OPEN Call Zaproszenie do składania wniosków Data not available System finansowania Data not available Koordynator University of Southern Denmark - Odense University Wkład UE Brak danych Adres Campusvej 55 5230 Odense M Dania Zobacz na mapie Koszt całkowity Brak danych Uczestnicy (3) Sortuj alfabetycznie Sortuj według wkładu UE Rozwiń wszystko Zwiń wszystko Division of Ion Physics Szwecja Wkład UE Brak danych Adres Lagerhyddsv. 1 75121 Uppsala Zobacz na mapie Koszt całkowity Brak danych Russian Academy of Sciences Rosja Wkład UE Brak danych Adres Leninsky Prospect 38/2 117829 Moscow Zobacz na mapie Koszt całkowity Brak danych Russian Academy of Sciences Rosja Wkład UE Brak danych Adres 151 Prospect Octyabrya 450075 Ufa Zobacz na mapie Koszt całkowity Brak danych
