影像系统

The ability to quantify miRNA abundance at the single-cell level and image its spatial distribution could lead to unique insight into the biological roles of miRNAs and miRNA-associated gene regulatory networks. This protocol describes a method for quantitatively imaging miRNAs in s ...

Recently, several protocols for labeling of stem cells with superparamagnetic iron oxides (SPIOs) have been developed, leading to an active and growing field aimed at visualizing stem cells using MRI (magnetic resonance imaging), including image-guided stem cell injections. This d ...

Characterization of the distributions of specific proteins and lipids within cellular membranes is currently a major challenge. Advances in secondary ion mass spectrometry (SIMS) now enable the distributions of isotopically labeled lipids within cellular or model membranes to ...

Soft X-ray microscopy is ideally suited to visualizing and quantifying biological cells. Specimens, including eukaryotic cells, are imaged intact, unstained and fully hydrated, and therefore visualized in a near-native state. The contrast in soft X-ray microscopy is generated by the ...

Innovative approaches for real-time imaging on molecular-length scales are providing researchers with powerful strategies for characterizing molecular and cellular structures and dynamics. Combinatorial techniques that integrate two or more distinct imaging modal ...

Investigation of intracellular dynamics requires a detailed description of the molecular topography and ultrastructural morphology of the cell, for example, the position of a protein in relation to a given compartment of the cell and the morphology of the compartment. Standard fluor ...

The cell nucleus contains many distinct subnuclear compartments, domains, and bodies that vary in their composition, structure, and function. While the cellular constituents that occupy the subnuclear regions may be well known, defining the structural details of the molecular asse ...

The desire to directly probe biological structures on the length scales that they exist has driven the steady development of various high-resolution microscopy techniques. Among these, optical microscopy and, in particular, fluorescence-based approaches continue to occupy do ...

The real-time visualization of specific binding sites on biological samples with high spatial resolution, in order of several nanometers, is an important undertaking in many fields of biology. During the past 5 years, simultaneous topography and recognition imaging (TREC) has become a p ...

Structural analysis of transmembrane proteins remains a challenge in biology, mainly due to their difficulty in being overexpressed and the required use of detergents that impair different steps of biochemistry classically used to obtain 3D crystals. In this context, we have develop ...

This chapter reviews amplitude modulation (AM) AFM in air and its applications to high-resolution imaging and interpretation of macromolecular complexes. We discuss single DNA molecular imaging and DNA–protein interactions, such as those with topoisomerases and RNA polymera ...

In this chapter, we describe types of gold nanoparticle–biomolecule conjugates and their use in electron microscopy. Included are two detailed protocols for labeling an IgG antibody with gold monolayer protected clusters. The first approach is a direct bonding approach that utilizes ...

Integration of a scanning electron microscope (SEM) and focused ion beam (FIB) technology into a single FIB/SEM system permits use of the FIB as a nano-scalpel to reveal site-specific subsurface microstructures which can be examined in great detail by SEM. The FIB/SEM technology is widely used ...

With recent improvements in instrumentation and computational tools, serial section electron microscopy has become increasingly straightforward. A new method for imaging ultrathin serial sections is developed based on a field emission scanning electron microscope fitted ...

Cryo electron tomography is a technique that allows visualization of biological specimens in three dimensions with nanometer resolution. For cryo immobilized life sciences samples it can reveal cellular morphology, the shape of membranous structures, and depict internal macr ...

Over the past decades there have been significant advances in transmission electron microscopy for biological applications, including in energy filtering and spectrum imaging, which are techniques based on the principles of electron energy loss spectroscopy. These imaging mo ...

Scanning transmission electron microscopy (STEM) in the dark-field mode of operation is a technique regularly used to record high-contrast images from isolated macromolecular assemblies at nanometer resolution. Dark-field STEM images are unique in that they can be readily quant ...

In this chapter we describe the steps needed for reconstructing the three-dimensional structure of a macromolecular complex starting from its projections collected in electron micrographs. The concepts are shown through the use of Xmipp 3.0, a software suite specifically designed f ...

Over the past decade, fluorescence microscopy has been revolutionized by the development of novel techniques that allow near-molecular resolution. Many such methods—collectively referred to as “single-molecule localization microscopy” (SMLM)—are based upon the repeated ...

Recently, a new approach for super-resolution microscopy has emerged which is based on the successive localization of single molecules. The majority of molecules are prepared to reside in a nonfluorescent dark state, leaving only a few single molecules fluorescing. The single molecul ...