Formaldehyde is one of the most rapidly penetrating fixatives used. Unfortunately, it is one of the slowest to fix tissue. This paradox was finally explained by Burnett in 1982. An fine description of the properties of formaldehyde may be found in John Kiernan's book.

The penetration rate of formaldehyde in mm/hr is a variable thing. It depends on how the data is obtained. It may also vary slightly depending on tissue type. The penetration rate of formaldehyde fixatives has been extensively studied, often with conflicting results. The penetration of non-coagulating fixatives is difficult to measure.

Mechanical properties of cells are determined by the dynamic behavior of the cytoskeleton and physical interactions with the environment. The cytoskeleton, composed of actin filaments, intermediate filaments, and microtubules, is vital for numerous key cellular processes, such as cell division, vesicle trafficking, cell contraction, cell motility, and cell signaling. There is increasing evidence that deregulation of cytoskeletal components like disassembly of actin and tubulin filaments is an important parameter in cellular pathology. Thus, significant alterations of the mechanical phenotype of the cell and its surrounding microenvironment are reported to be involved in aberrant cellular processes and successively contribute to onset and progression of diseases such as cancer, malaria, and possibly neurodegeneration. In vitro and ex vivo biomechanical studies have shown that cancer cells have significantly decreased elastic moduli than their normal counterparts, a characteristic that is attributed to the ability of cancer cells to metastasize or spread.

HyperionTM is a newly developed high-performance ion source that significantly advances the capabilities of many ion beam techniques used by material scientists and engineers. Hyperion has been developed to provide focused beams as small as 10 nm, beam currents up to several micro-Amps, and a broad range of ion species that include He+, O2+, Xe+ and H3+.

Fundamental research within the scope of cell and structural biology as well as nano-technology is increasingly focusing on unraveling interactive biological and biochemical processes and pathways at the macromolecular level. For this, high resolution transmission electron microscopy (TEM) is indispensable. Of paramount importance is the three-dimensional visualization of macromolecular structures and molecular machines in their native hydrated state. Their physical fixation within ultra-thin vitrified ice layers is the crucial starting point.

All living creatures, including humans, are made of cells. The majority of life forms exist as single cells that perform all functions to continue independent life. Some cell structures, cell organelles and particularly bacteria and viruses are commonly too small to be fully observed with an optical microscope. Therefore, an electron microscope is required. Since samples examined with an electron microscope are exposed to very high vacuum, it is impossible to view living cells. The sample preparation for electron microscopy requires that living cells be killed, frozen, dehydrated, and impregnated with heavy metals.

Over the past decade the Atomic Force Microscope has been utilised in a myriad of applications across many fields of research and industry. One area that has been of particular interest is the measurement of small scale forces. The AFM is capable of measuring electrostatic and van der Waals forces with high precision based on small deflections of the AFM cantilever.

The forces between colloidal particles dominate the behaviour of a great variety of materials. The AFM has been extensively used to measure the forces between planar surfaces and individual colloid particles. One of the key driving forces for such experiments and the corresponding theoretical framework that has ensued is the ease of use of standard AFM tips for such measurements.

Most of the specimens for high-resolution electron microscopy have amorphous surface layers due to contamination during observation and/or damaged surface layers during specimen preparation. Moreover, many specimens are radiation sensitive, and a part of the specimen easily becomes amorphous during the observation. These amorphous materials make clear observation of crystal structure difficult. A periodic structure may be extracted by simply using a periodic mask in Fourier space. However, this kind of mask often introduces a periodic feature in addition to the crystal structure. To reduce such artifacts a Wiener filter or an average background subtraction filter has been discussed. However, these filters do not work for non-ideal crystals, such as cylindrical crystals and nano-crystals, where a translational periodicity is limited to the order of nano-meter. In this report we improve these filters by introducing new ways to estimate a contribution from the amorphous materials.

Images produced by an atomic forces microscope (AFM) often contain spurious features and image distortion that can render accurate imaging and metrology suspect. These “artifacts” are caused by the manner in which the image is produced. Artifacts can originate from the probe tip geometry, scanner non-linearity, image processing software, vibration, sample contamination, electronic noise, and poor sample stability. This article describes and illustrates common AFM image artifacts and suggests means to eliminate or minimize them.

In 1965, Gordon Moore forecast that the microprocessor industry would continually scale to smaller feature sizes and the number of transistors would double every 18 months. Scaling below the 100nm node, combined with the implementation of copper and low dielectric constant insulators to increase the processor speed, has produced the situation in which SEM inspection no longer offers suitable resolution to image key artifacts and structures. The transmission electron microscope (TEM), once considered more of a development tool, is now in the forefront for process control and failure analysis, especially for measurements such as the thickness of semiconductor device non-planar barrier and seed layers

The current use of microwave technology in science creates a dichotomy. Is it the heat or is it the energy? One entire branch of science, chemistry, uses microwave energy to apply heat to a broad range of chemical processes, under pressure, to produce the desired end-products quickly and efficiently (1). The biological sciences, surgical pathology in particular, have tried to adapt the microwave oven to speed up a broad range of processes: fixation, decalcification, antigen retrieval, tissue processing for paraffin and plastic embedding, and histological staining, including special stains, immunolabeling, and in situ hybridization (2). The biologists have assumed that they are also applying heat to speed processing. However, recent improvements in the microwave suggest that the energy is the critical variable (9). We have designed fixation experiments to test the two views.

The development of laser-assisted atom probe tomography (APT) and specimen preparation techniques using a focused ion beam equipped with high-resolution scanning electron microscopy (SEM) has significantly advanced the characterization of semiconductor devices by APT. The capability of APT to map out elements in devices at the atomic scale with high sensitivity meets the characterization requirements of semiconductor devices such as the determination of elemental distributions for each device region.

A unique class of impurity-based quasi-liquid films has been widely observed at free surfaces, grain boundaries (GBs), and hetero-phase interfaces in ceramic and metallic materials (Figure 1). These nanometer-thick interfacial films can be alternatively understood to be: (a) quasi-liquid layers that adopt an “equilibrium” thickness in response to a balance of attractive and repulsive interfacial forces (in a high-temperature colloidal theory) or (b) multilayer adsorbates with thickness and average composition set by bulk dopant activities [1–2]. In several model binary systems, such quasi-liquid, interfacial films are found to be thermodynamically stable well below the bulk solidus lines, provoking analogies to the simpler interfacial phenomena of premelting in unary systems [3] and prewetting in binary de-mixed liquids [4]. These interfacial films exhibit structures and compositions that are neither observed nor stable as bulk phases, as well as transport, mechanical, and physical properties that are markedly different from bulk phases.

The technique of embedding TEM specimens in polymer resins for subsequent ultra-thin sectioning is well established. For geological materials, this protocol prevents specimen damage introduced by ion beam thinning, and is often used for preparing friable or porous materials. However, traditional polymer-based embedding resins may introduce organic carbon contaminants, producing artifacts in carbon analyses. Thus, a carbon-free substitute for traditional embedding media is required to ensure accurate carbon analyses of embedded and ultramicrotomed TEM specimens.

A suitable technique that was first reported by Bradley is to embed specimens in pure sultur. In this technique, the specimen is immersed in liquid sulfur, the liquid is solidified, and the resulting block is ultramicrotomed as with traditional resins. Since sulfur has a high vapor pressure at room temperature, the ultra-thin sections are then placed in a separate vacuum chamber to sublimate the sulfur, yielding TEM specimens free of any embedding medium.