Cryo-electron tomography (cryo-ET) is a powerful technique that can provide unprecedented insight into protein-protein interactions and molecular machinery in a near-native state. The adoption of cryo-ET by life science research groups is hampered by the challenges associated with cryo-ET sample preparation. The current sample preparation process has many steps at which ice contamination may occur to negatively affect the final sample and data quality. A survey was conducted to better understand the effects and impact of ice contamination to the cryo-ET outcome. Over 80 cryo-electron microscopy users worldwide participated in our survey. The results are presented in this article. We furthermore discussed the currently available solutions that can alleviate the ice contamination problems to increase the sample yield and cryo-ET data output.

Fourier ptychography is an emerging computational microscopy technique that can generate gigapixel-scale images of biological samples. With only the addition of a low-cost LED array to a standard digital microscope and a reconstruction algorithm, Fourier ptychography overcomes the fundamental trade-off between a microscope's resolution and field-of-view without any moving parts. This article is the first in a three-part series that aims to introduce the fundamentals of the technology to the broader microscopy community and beyond, using intuitive explanations.

Scanning electron microscopes (SEMs) are a popular analytical tool due to their high spatial resolution, large depth of field, and analytical capabilities. However, in many cases, the large-scale installation and cost of SEMs can be a barrier to entry for smaller laboratories or facilities. The introduction of a more compact benchtop SEM has changed the landscape, enabling scientists in many fields to adopt the technology and revolutionize research. Benchtop SEMs can be used in a variety of industries including materials science, pharmaceutical research, energy exploration, science education, and academia. These industries require analysis at the nanoscale for quality control, failure analysis, and R&D, for all of which the benchtop SEM is perfectly positioned to provide necessary detail. These advantages and new developments in the technology have made the benchtop SEM a widely available and well-accepted tool.

The internal electric field of a 2D P-N junction of a semiconductor is mapped out by two techniques: measuring the deflection of the transmitted beam in micro-STEM mode with acquisition and data fitting of an un-scattered beam image, and through the derivative of electrostatic potential maps by dual lens electron holography. Comparable results of the P-N junction internal electric field measured with these two techniques are reported.

Super-resolution microscopy gives researchers invaluable opportunities and continues to make great strides in terms of performance and applicability. Clever developments in stimulated emission depletion (STED) microscopy have pushed the doors open wider for many applications. Here, we discuss three examples: first, how time-resolved detection unlocks new information; then, live-cell imaging enabled by intelligent illumination schemes; and finally, deep tissue imaging with dynamic aberration correction. As an outlook, we examine MINFLUX as an approach for molecular resolution with fluorescence.

This is the third article within a three-part series on Fourier ptychography, which is a computational microscopy technique for high-resolution, large field-of-view imaging. While the previous articles introduced the working principles of the technique, in this article we focus on the practical benefits that it brings to the imaging community. We present a didactic overview of the most important and well-established practical use-cases such as gigapixel imaging, quantitative phase contrast, thick sample imaging, and aberration metrology. We also discuss how Fourier ptychography can leave the visible light domain and venture into the realm of smaller wavelengths such as X-rays and electrons, among other topics.

Over the past three decades, atomic force microscopy (AFM) has undergone a series of design changes to attain a flat XY scan and stable non-contact mode in ambient atmosphere. AFM has evolved into an ideal method for non-destructive scanning of samples with longer probe tip life, high accuracy, repeatability, and automation. Together with self-optimizing algorithms for scan parameters in the non-contact mode, AFM can become as widely adopted as other microscopies such as optical or scanning electron microscopy (SEM). Even full automation of AFM probe tip exchange is now possible with probe type recognition software and laser beam alignment on the cantilever and position-sensitive photo diode (PSPD). By separating the optics stage from the Z stage, an AFM system can be made with low mechanical noise and improved optical vision.

As part of the Hitachi High-Tech America Inspire STEM Education Outreach Programme in the UK, a successful STEM (Science, Technology, Engineering and Math) education pilot has seen over 5000 students from 80 schools given the opportunity to use scanning electron microscopes (SEMs) for their own experiments. The collaborative project allowed students to design, propose, and execute experiments to give them hands-on experience with scientific research. Feedback from the project has been resoundingly positive, with many students gaining new skills and an interest in STEM, and it looks set to grow further to allow more students access to high-level scientific equipment.

Here, we use a variety of microscopic imaging techniques, including scanning electron microscopy, 3D visible light microscopy, and portable microscopy to capture the topography of rough paper. Paper coated with a model soot was cleaned with either a firm vinyl eraser or softer, putty-like kneaded eraser and reimaged to characterize the disposition of remaining soot. Although both methods remove soot from the upper-most surface of the paper, only the kneaded eraser can conform to the complex topography to remove soot from the interstices between paper fibers.

This article is the second within a three-part series on Fourier ptychography, which is a computational microscopy technique for high-resolution, large field-of-view imaging. While the first article laid out the basics of Fourier ptychography, this second part sheds light on its algorithmic ingredients. We present a non-technical discussion of phase retrieval, which allows for the synthesis of high-resolution images from a sequence of low-resolution raw data. Fourier ptychographic phase retrieval can be carried out on standard, widefield microscopy platforms with the simple addition of a low-cost LED array, thus offering a convenient alternative to other phase-sensitive techniques that require more elaborate hardware such as differential interference contrast and digital holography.

Foldscope Instruments, Inc. creates and distributes low-cost, high-quality scientific tools to communities around the world to help advance education, research, and medical diagnostics. The Foldscope—a high-quality microscope created for less than a dollar in parts—was created in 2015. To date, the Foldscope has reached 1.6 million people worldwide in over 160 countries. A few notable uses for the Foldscope include identification of microscopic eggs of agricultural pests in India, creation of a catalog of the biodiversity of soil arthropods in the Amazon, detection of fake currency and medicine, following toxic blooms, detection of bacteria in water samples, and mapping of pollen diversity in a city landscape.

Temperature is a key parameter in most biological and physical systems. It is, however, an inherent technological challenge to precisely track and control the temperature of small sample volumes when using high- and super-resolution microscopes. Various effects can cause a deviation of the sample temperature from its expected value, specifically in the observed volume or field-of-view. These effects include direct thermal contact of the objective lens and the coverslip via immersion medium, illumination-induced heating, evaporative cooling, or triggered phase transitions. In this paper, we shed light on these phenomena and introduce our newly developed device VAHEAT, which follows a microscopic approach for controlling and measuring the sample temperature. Our system overcomes traditional limitations of temperature sensing and controlling in high-sensitivity microscopy applications, leading to more reproducible experimental results and conquering new experimental parameter ranges.

Many universities, commercial companies, and science organizations who use microscopy have outreach programs. The members of such generally love to share their enthusiasm and passion with the next generation. Content and confidence on providing such a program often comes from sharing ideas with like-minded scientists. These programs are typically delegated with the acronym STEM or STEAM: science, technology, engineering, art, and math. One of MSA's outreach programs is ProjectMICRO. Included are some STEAM ideas to share.

This article introduces a training simulator for electron beam alignment using Ronchigrams. The interactive web application, www.ronchigram.com, is an advanced educational tool aimed at making scanning transmission electron microscopy (STEM) more accessible and open. For experienced microscopists, the tool offers on-hand quantification of simulated Ronchigrams and their resolution limits.