Sub-cellular imaging of Cu in single cells via laser ablation-ICP-mass spectrometry

For years, GhEnToxLab has had a fascinating collaboration with UGhent’s Atomic and Mass Spectrometry group (A&MS), which has lead to multiple joint papers. Now, the A&MS group - led by Prof. Dr. Frank Vanhaecke – is developing another radically innovative tool to quantify the elemental composition of single cells. Using laser ablation inductively coupled plasma-mass spectrometry (LA-ICPMS), the accumulation of Cu in a metal exposed marine dinoflagellate, Scrippsiella trochoidea, was measured. In this way, the mean Cu concentration in the cells was determined across different exposure levels, and the accuracy, efficiency and ability for high through-put of this promising technique was established.

Scientific abstract

This manuscript describes the development and characterization of a high-density microarray calibration standard, manufactured in-house, and designed to overcome the limitations in precision, accuracy and throughput of current calibration approaches for the quantification of elemental concentrations on the cellular level using laser ablation inductively coupled plasma-mass spectrometry (LA-ICPMS). As a case study, the accumulation of Cu in the model organism Scrippsiella trochoidea resulting from transition metal exposure (ranging from 0.5 to 100 µg/L) was evaluated. After the Cu exposure, cells of this photosynthetic dinoflagellate were treated with a critical point drying protocol, transferred to a carbon stub and sputter-coated with a Au layer for scanning electron microscopy (SEM) analysis. In subsequent LA-ICPMS analysis, approximately 100 cells of each population were individually ablated. This approach permitted to evaluate the mean concentration of Cu in the cell population across different exposure levels, and also allowed to examine the cellular distribution of Cu within the populations. In a cross-validation exercise, subcellular LAICPMS imaging was demonstrated to corroborate synchrotron radiation confocal X-ray fluorescence (SR-XRF) microimaging of single cells investigated under in vivo conditions.

Full reference (link)

Van Malderen SJM, Vergucht E, De Rijcke M, Janssen CR, Vincze L, Vanhaecke F. 2016. Quantitative determination and subcellular imaging of Cu in single cells via laser ablation-ICP-mass spectrometry using high-density microarray gelatin standards. Anal. Chem. 88 (11) 5783–5789.