Medicine and forensics

The resolution of conventional optical microscopes and x-ray tomography systems is insufficient to understand the structural information of biological samples on a micro- and nanoscale. With JEOL electron microscopes it is possible to image and three-dimensionally reconstruct not only the smallest of biological structures such as viruses, but also microscale objects such as synapses or cells.

Reconstruction of a bacteriophage (left) and synapses (right)

Source data: Journal of Structural Biology 177 (2012) 589–601 and JEOL News 51

These days, biocides are used extensively for pest control in agriculture. The quantitative determination of the toxic residues of the applied pesticides is of vital importance for the authorisation of agricultural products. JEOL high-resolution analytical instrument are capable of detecting biocides quickly and simply, even with the smallest of concentrations.

Mass spectrum of various herbicides

Source data: JEOL Ltd. / DART Application Notes, page 57

The surface of lotus leaves can serve as a model for self-cleaning surfaces. The exact characterisation of these surfaces is vital in order to be able to recreate them. The surface of lotus leaves comprises small wax tubes that can be easily destroyed during examination with an electron beam. JEOL therefore offers tailor-made solutions that thermally stabilise the samples in a controlled manner and thus prevent them from being destroyed by the observation.

Surface of a lotus petal. The wax tubes have a diameter of approx. 50 nm

Source data: JEOL (Germany) GmbH

Cryo electron microscopy  and the analysis of protein structures has undergone drastic changes since the last years. This technique was awarded the Nobel Prize in Chemistry 2017 (https://www.nobelprize.org/nobel_prizes/chemistry/laureates/2017/advanced-chemistryprize2017.pdf).
With the introduction of fast and highly sensitive camera techniques as well as dedicated, automated electron microscopes resolutions of 2 Ångström and lower could be achieved under near to native conditions. This single particle analysis method (SPA) allows to efficiently determine the structure of non crystalline proteins in order to design new drugs or to resolve the fundamental functions of biochemical or molecular biological processes.

GroEL protein at 40k x magnification (pixel size 0.12 nm), detector: K2 summit, instrument: CRYO ARMTM200, Schottky 200kV, inset: reduced live FFT, zero-loss image with 20eV slit width

Source data: JEOL Ltd., University Osaka, Prof. Namba

DNA origami is a new technology in synthetic biology, or rather the disciplines of biochemistry and biophysics. It involves DNA molecules being turned into random two- and three-dimensional nanoforms. These synthetically folded DNA molecules are used as e.g. future biocompatible carriers for active substances or to produce nanomachines or nanorobots.

Negatively contrasted TEM image of synthesised DNA molecules

Source data: JEOL (Germany) GmbH, Technical University of Munich, Prof. Dietz and Klaus Wagenbauer.

Specific preparation methods must be used for the high-resolution imaging and analysis of biological samples in an electron microscope. Food stuffs and their constituents in particular can only be imaged artifact-free through active cooling. JEOL electron microscopes are therefore prepared as standard for the installation of cryogenic systems so that sensitive samples can be prepared externally, transferred in a cooled state and subsequently examined in a cryogenic mode of operation.

Electron microscope image of powdered milk

Source data: JEOL (Germany) GmbH, DIL Quakenbrück

Magnetotactic bacteria orientate themselves along the Earth's magnetic field with the help of magnetite particles enveloped in a membrane. These organisms serve as a model for examining the complex processes of biomineralisation. Entities known as magnetosomes (comprising magnetite crystal and membrane) are also tested as carriers for active substances and for new forms of therapy in medicine (hyperthermia therapy). JEOL supplies combined and fully automated solutions for the high-resolution elementary classification of the individual constituents.

Element analysis (red rectangle) at 120 kV in S(TEM) on magnetotactic bacteria, magnetite chains (green)

Source data: JEOL (Germany) GmbH

To achieve the high-resolution imaging and analytics of biological samples, it is often necessary to examine the sample in its native state. Thanks to the patented JEOL Aqua Cover, it is even possible to image moist or hydrated samples in a scanning electron microscope at low pressure.

Image of a water droplet on the surface of a rose petal

Source data: JEOL Ltd. (Aqua Cover presentation)

The linking of light microscopy signals and electron-optical details allows, among other things, conclusions to be drawn regarding the exact location of proteins in specific sections of tissues. JEOL manufactures intuitive, multi-system complete solutions for combining fluorescence and high-resolution electron microscopy.

Thin section of a zebra fish: correlatively superimposed electron and fluorescence microscopic images

Source data: JEOL (Germany) GmbH, Centre for Regenerative Therapies, TU Dresden.

The colours of a butterfly wing are created by pigment or structural colours. Due to the delicate surface of the wing, it is mechanically impossible to prepare a cross-section. With JEOL preparation systems and scanning electron microscopes, even fragile, organic structures can become accessible and visible.

Image of a cross-section through a butterfly wing (Morpho)

Source data: JEOL Ltd., Cross Section Polisher brochure

As part of a biopsy, tissue is removed and subsequently examined under the microscope. Labels can also be used to pinpoint the location of active substances to be examined. JEOL not only supplies specially developed, automated systems for simple and high-constrast imaging and high-resolution and ultrastructural diagnostics. With highly sensitive JEOL EDX detectors, it is also possible to pinpoint the location of the labels used.

TEM image of a tissue section

Source: JEOL (Germany) GmbH, Demo Friedrich Baur Institut in Munich