Apr. 16, 2013

Targeted Subcellular Nanoanalysis

We developed a new approach using cryo-correlative light and scanning transmission electron microscopy allowing analysis of targeted in situ intracellular ions and water measurements at the ultrastructural level within domains identified by examination of specific GFP-tagged proteins [1]. We illustrate the potential of this approach by investigating changes in water and ion content in nuclear domains identified by GFP-tagged proteins in cells stressed by Actinomycin D treatment and controls. moreMar. 04, 2013

New Insights on Electron Channeling

Electron channeling contrast imaging (ECCI) is a powerful technique for the quantitative characterization of deformation structures in the SEM. The coupling of ECCI with EBSD provides an efficient method to attain enhanced diffraction contrast in the SEM. The EBSD-based ECCI set-up allows the imaging of dislocation and nano-twin substructures in the SEM. Some examples of quantitative microstructural characterization on structural materials are provided.
moreFeb. 25, 2013

SEM and ESEM Observation of Stem Cells

Studying biological samples with scanning electron microscopy has specific requirements for their preparation. Sample drying is a particularly critical operation for objects such as cultured cells. The requirement for damaging drying step can be eliminated using environmental scanning electron microscopy. This study compares dried and wet samples of cultured human embryonic stem cells. It points to the advantages of both methods and to the complementarity of the information that they provide.
moreJan. 25, 2013

Archeological Pottery SEM-EDS Analysis

Archaeologists have identified several types of pigments used in ancestral Puebloan black-on-white painted pottery from the American Southwest. One type of pigment contains iron. The most widely used and available method of determining the elemental composition of these pigments has been scanning electron microscopy utilizing energy dispersive spectrometry (SEM-EDS).
moreJan. 08, 2013

Dynamic Wettability Study at Nanoscale

Quantitative wettability study at nanoscale was developed using transmitted electrons in the environmental scanning electron microscope. Water condensation was studied for the initial stages of nucleation and growth over nano-thick self supported water films. Irregularities at the water film boundaries constituted nucleation sites for filmwise and dropwise condensation. In situ imaging provided nanodroplet growth power law dependence and a dynamic study of coalescence events.
moreDec. 20, 2012

Morphology of Nanoparticles

Potential candidates of reference nano-materials are manufactured and systematically characterized in particular with respect to their morphology (shape, size and size distribution) in the frame of the running large European project NanoValid. By exploiting the transmission operation mode in a SEM, known as T-SEM, it is demonstrated by means of three representative examples of nanoparticles how a quick morphological inspection up to a complete, metrological characterization is feasible.
moreDec. 13, 2012

VP-SEM: Unsung Hero of SEM Imaging

Variable Pressure Scanning Electron Microscopy (VP-SEM) has become an important tool for the imaging of hydrated specimens and samples with low conductivity. This article outlines various research scenarios where VP-SEM allowed minimal sample processing that often enabled successive specimen reuse. We present cases where these characteristics allowed imaging of specimens otherwise impossible using conventional SEM methods.
moreOct. 22, 2012

Pitfalls in the Measurement of FIB Beam Size

Focused ion beam (FIB) systems using heavy ions such as Ga are widely used for machining at the 10 - 100 nm level. In order to be able to perform this function precisely it is necessary to have an accurate estimate of the beam size. The commonly used method to measure FIB size is the rise distance method, well known in scanning electron microscopy (SEM), but this is subject to a number of errors that can result in an estimate that is optimistic relative to the true beam size. more