Multimodal Imaging of Chemically Fixed Cells in Preparation for NanoSIMS

Abstract

In this work, we have employed time-of-flight secondary ion mass spectrometry (ToF-SIMS) to image chemically fixed adrenal cells prepared for transmission electron microscopy (TEM) and subsequent high-spatial-resolution NanoSIMS imaging. The sample fixation methodology preserves cell morphology, allows analysis in the ultrahigh vacuum environment, and reduces topographic artifacts, thus making these samples particularly favorable for ToF-SIMS analysis. ToF-SIMS imaging enables us to determine the chemistry and preservation capabilities of the chemical fixation as well as to locate specific ion species from OsO4. The OsO4 species have been localized in lysosomes of cortical cells, a type of adrenal cell present in the culture. NanoSIMS imaging of the (190)Os(16)O(-) ion species in cortical cells reveals the same localization as a wide range of OsO4 ions shown with ToF-SIMS. Even though we did not use during NanoSIMS imaging the exact OsxOy(-) ion species discovered with ToF-SIMS, ToF-SIMS allowed us to define the specific subcellular features in a high spatial resolution imaging mode. This study demonstrates the possibility for application of ToF-SIMS as a screening tool to optimize high-resolution imaging with NanoSIMS, which could replace TEM for localization in ultrahigh resolution imaging analyses.

In Vitro Tracking of Intracellular Metabolism-Derived Cancer Volatiles via Isotope Labeling

“… 37 The corrected MDV of intracellular metabolites was mapped onto the central carbon metabolism pathway using VANTED 38 connected to SBGN plugin. 39 NanoSIMS data were analyzed using WinImage software (Cameca) to obtain 13 C 14 N/ 12 C 14 N and 12 C 14 N images and ImageJ 40 with openMIMS plugin 41 software (MIMS, Harvard University, Cambridge, MA; ) to extract the values of each detected ion. Linear regression analysis and Pearson’s correlation coefficient for VOCs, and Michaelis–Menten equation for calculating isotopic steady state were performed using Graphpad Prism 7.0 software (Graphpad Software, Inc., San Diego, CA).…”

SIMS imaging in neurobiology and cell biology

“…The lysosome was identied as a main accumulation region of OsO 4 . 69 Veith and colleagues combined SIMS with fast micro X-ray uorescence spectroscopy (m-TRF) to detect CeO 2 particles in biological tissue sections. 70 m-TRF allows a fast elemental analysis of big tissues, such as lung tissue.…”

Synthesis of plasmodione metabolites and13C-enriched plasmodione as chemical tools for drug metabolism investigation

“…The IC50 values of the different 13 C-enriched plasmodiones against P. berghei blood stage parasites confirmed that the 13 C-enrichment did not affect the antimalarial activity of the lead drug. The uniformly 13 C-enriched plasmodione will be used to elucidate the drug metabolism studies 41 and the cellular localization of the drug and its metabolites using nanoSIMS imaging 42,43,44 . In addition to the 13 C-labeled compounds, we prepared a series of putative plasmodione metabolites.…”