Laser microdissection inductively coupled plasma mass spectrometry (LMD-ICP-MS): A novel tool for bioimaging of metals to single cell level

摘要

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been established as a powerful elemental imaging technique in routine mode for biological tissue with spatial resolution on the 12 - 160 (mu)m scale. For the quantitative bioimaging of metals in thin tissue sections the spatial resolution of LA-ICP-MS has to be improved to the low micrometre scale and below. To achieve this spatial resolution of LA-ICP-MS we created a new experimental arrangement using a laser microdissection system (LMD) for tissue ablation coupled together with a sensitive quadrupole-based inductively coupled plasma mass spectrometer (ICP-QMS, XSeries 2, Thermo Scientific, Bremen) for the analysis of ablated material. A flat laser ablation chamber made of glass was inserted into the LMD, fitted to the microscope slide with the specimen. The biological tissue fixed on the glass slide was ablated using the focused solid-state Nd:YAG laser of the LMD. The laser ablation chamber was then connected directly to the ICP-MS using standard Tygon tubes.