- Day 2, May 16（Thu.） 09:30-09:50 Room B (102)
Atmospheric Pressure Laser Ionization Imaging Mass Spectrometry at Intracellular Scale Using Transmission Geometry Optical System
Imaging mass spectrometry (IMS) is a technique for visualising the spatial distributions of molecules by scanning a focused laser on a sample. Although lateral resolution less than 1 μm is required to observe intracellular molecules, the latest products offer resolution limited to about 5 μm. Since the laser focusing lens needs to be placed within about 10 mm from the sample plate to obtain a spot size of 1 µm, the focusing lens interferes with the ion optics. Incorporation of a transmission geometry optical system in which laser is irradiated from the rear of a sample has been considered for high-resolution IMS. Furthermore, the development of atmospheric-pressure laser ionisation is necessary for the simplification of sample preparations and live cell analyses. Therefore, an ion source using the transmission geometry optical system combined with atmospheric-pressure laser ionisation has been developed, and IMS was conducted at 1 μm spot size at a subcellular scale for human prostate cancer cells PC-3 stained with crystal violet (CV). It is suggested that IMS at intracellular scale can be conducted using the transmission geometry optical system. Furthermore, improvement on the collection efficiency will contribute to enhancing the contrast of the ion image.