High‐resolution water window X‐ray imaging of in vivo cells and their products using LiF crystal detectors

Abstract

High contrast imaging of in vivo Chlorella sorokiniana cells with submicron spatial resolution was obtained with a contact water window X-ray microscopy technique using a point-like, laser-plasma produced, water-window X-ray radiation source, and LiF crystals as detectors. This novel type of X-ray imaging detectors is based on photoluminescence of stable electronic point defects, characterized by high intrinsic resolution. The fluorescence images obtained on LiF crystals exposed in single-shot experiments demonstrate the high sensitivity and dynamic range of this new detector. The powerful performances of LiF crystals allowed us to detect the exudates of Chlorella cells in their living medium and their spatial distribution in situ, without any special sample preparation.

Contact X‐ray microscopy of living cells by using LiF crystal as imaging detector

“…The observation of the cellular exudate, very clear in Figure , given by the high absorption contrast in the water‐window soft X‐rays, is rather difficult to obtain with other microscopy techniques (Bonfigli et al ., ).…”

“…(). These radiation imaging detectors showed a great range of applications and allowed observing cell structures (cell exudates, dry pollens, internal structures) not easily visible by other techniques (Bonfigli et al ., , , ; Reale et al ., ). The peculiarities of luminescent LiF detectors (Baldacchini et al ., ), like high spatial resolution over a large field of view, wide dynamic range (i.e.…”

Cryo-electron tomography of bacteria: progress, challenges and future prospects

“…The use of labelling methods may be useful not just for electron tomography, but for a complementary approach that uses soft X-rays to obtain 3D images of frozen cells at resolutions that may exceed 100 nm in the near future. Although initial experiments were carried out using synchrotron sources, which guarantee a high photon flux 57 , there is now an increase in the availability of simpler laboratory radiation sources 58 and tabletop sources [59][60][61] that can provide in-house 3D cellular imaging. Despite the modest resolutions attained with these methods, they may still be valuable for protein localization by tagging proteins with X-ray opaque probes such as gold and using detection strategies based either on simple absorption or using specific absorption edges of atoms such as titanium (TiO 2 nanoparticles) for differential imaging 62 .…”

Soft x-ray free-electron laser imaging by LiF crystal and film detectors over a wide range of fluences

“…(square-centimeter scale) with submicrometer spatial resolution [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Detection is by a readout postprocess that is based on optically stimulated photoluminescence (PL) from point defects in LiF crystals or film.…”