Three-Dimensional Correlative Imaging of a Malaria-Infected Cell with a Hard X‑ray Nanoprobe

Benefiting
from the recent advances of synchrotron X-ray nanoprobes,
we demonstrate three-dimensional (3D) correlative nanoimaging on malaria-infected
human red blood cells. By combining X-ray fluorescence tomography
and phase contrast nanotomography on the same cell with sub-100 nm
pixel size, we establish a routine workflow from the data acquisition,
data processing, to tomographic reconstruction. We quantitatively
compare the elemental volumes obtained with different reconstruction
methods, with the total variation minimization giving the most satisfactory
results. We reveal elemental correlations in different cell compartments
more reliably on reconstructions as opposed to 2D projections. Finally,
we determine for the first time the 3D mass fraction maps of multiple
elements at the subcellular level. The estimated total number of Fe
atoms and the total mass of red blood cells show very good agreement
with previously reported values.