Easy observation and filming of plankton

When investigating water samples within the framework of hydrobiology, it is very easy to observe and film plankton with the Motic AE31E inverted microscope and the Moticam 1080 camera. The plankton containing water sample is stored in a culture dish, the bottom of which is formed by a calibrated cover glass. The dish is simply placed on the microscope stage. The Moticam 1080 is connected to a monitor. As soon as an interesting organism appears on the monitor screen, it only needs a simple mouse click to record the image.

A Casuarina cunninghamiana from Australia

The Casuarina cunninghamiana or the River She-Oak is a large, fast-growing, pine-like tree native to the east of New South Wales and Queensland, Australia. The tree, an evergreen, has thin needle-like, flexible green twigs practically without leaves. An image of a cross section thereof is shown here. The epidermis shows a structure which is a little similar to that of pine needles.

The Casuarina cunninghamiana is one of the tallest trees of its kind and can reach a height of 30-35 m. Its straight stem branches are quite low and its bark is greyish brown, rough and cracked so that it often comes loose in strips. The plants can easily be grown from seeds. In some countries it is considered an invasive species because it can surpass indigenous plant communities.

How do you look after four times shedding your skin

An adult female mosquito lays her eggs on the water surface. This can be in a ditch, in pools in the floodplains, in a pond or in the rain barrel. Each species has its own preference. The number of eggs that are laid is very different from species to species and can be up to 300 at a time. After a few days, the larvae crawl out of the egg. These larvae feed on algae, microbes and other substances in the water.

No movement without motor nerve cells

Nerve cells or neurons are cells that you need for example when picking up a pen or in the reaction to contact with a hot or cold object etc. There are three types of nerve cells: sensory, motor and relay nerve cells.

Sensory nerve cells can be found throughout the body. The sensory nerve cells are the cells that collect information, e.g. if something hurts or feels hot or cold etc. The sensory nerve cells send this information to the central nervous system (brain and spinal cord) where it is processed.

Green light from the rocks of the Aladzha Monastery

The remains of the Aladzha Monastery on the Black Sea coast are located just above the port city of Varna, Bulgaria. In the very distant past, this monastery was carved out of a steep rock wall consisting of limestone. The monastery is formed by small caves situated at different levels in the rock wall.

In the photos of some pieces of limestone you can recognize the powdery structure of this soft limestone. 

However, let’s still have a look under the fluorescence microscope then; blue light excitation and FITC filter.  As can you see, green light, this white limestone shows auto fluorescence.

Panthera UC-Plan and diatoms

Diatom skeletons that are free of their content like chlorophyll etc. are excellent objects to test and compare the quality of microscope lenses. In this case, some pictures of the recently marketed Motic Panthera are shown.

The photos are stacked to show the sharpness over the entire length of the diatom. The actual microscopic images through the Panthera microscope are even sharper. Some sharpness is lost by the camera and the photo stacking program.

Basics of Light Microscopy: Incident Light Microscopy for opaque samples (II) - Dark Field

In the first part of our Incident Light Microscopy post we already explained the double function of the microscope objective in this kind of application field.

Playing an essential part in the imaging process is the task of every microscope objective. The manufacturer pays a lot of attention and spends remarkable efforts in creating a glass hardware for reliable and “close-to-truth” image results.

In incident light applications, the objective is additionally part of the illumination system. The lamp house sends light horizontally through the illumination axis. A semi-transparent mirror with a 45° orientation deflects the light and sends it through the objective. After reflection from the specimen surface, the light brings back sample information to the eyepieces and/or camera.

For the Darkfield method in an Incident light setup, this description is also valid. We just should know one more fact about optical reflection: The angle of Incidence is equivalent to the angle of Reflection.

Selecting the right microscope

BA Elite Series

Category: Advanced Transmitted Light Microscopes

Target specimen: Transparent samples (sections, smears, emulsions, water samples) from Biology & Medicine; rarely from Industry

Target customer: Lab technicians

This comparison is an approach for classifying different microscope models in a defined performance range. Here we are talking about Motic’s BA Elite series of Advanced Transmitted light microscopes, meant for routine work in university and biomedical lab. The comparison is meant to help you in finding a suitable solution for your lab.

The following chart is based on the specifications of the basic outfit for each model and its upgrade options. Our rating of the single specifications rests upon an individual understanding of the actual numerical values. This is a subjective rating, and we understand that each person might have its own opinion.

BA SERIES - Comparison Chart

We are not alone

In our body and on our skin live a lot of bacteria. On each human cell there are ten bacterial cells. This total of bacteria on and in our body is also called microbiome. Most of these are found in the large intestine: the intestinal flora. In an adult, the intestinal flora consists of 1014 (which are 100,000,000,000,000 bacteria). 99% thereof is strictly anaerobic.

Seeing the effect of radiation damage

The rock matrix contains quartz, plagioclase feldspar, microcline feldspar and biotite mica. The greenish brown flake of biotite shown in the centre exhibits many dark brown circular features resembling cigarette-type burns. These features are known as pleochroic halos and are a diagnostic feature of biotite. These halos are interesting as they are isotropic compared to the surrounding material which is anisotropic. The halo in the centre of field shows a small brightly coloured crystal of zircon which causes the dark brown effect due to a process called metamictization. This process is the radioactive decay and destruction of the crystal structure surrounding the zircon and the affected area becomes amorphous and hence isotropic.

How a small intestinal roundworm contributed to genetics

Cross-sections at the right place in the uterus of a female Ascaris megalocephala can be used to locate eggs in different stages of the first segmentation mitosis*.

After fixation and coloration of the sections, the chromosomes appear colored. The egg of this parasitic nematode can then serve as a support for studying the chromosomal phenomena that characterize the mitosis.

The grainy taste of pear flesh

Sclerenchyma cells are derived from parenchymal cells, which form secondary thickening edges in the cell wall. These are rich in lignin, which practically does not allow any substances getting through, which finally leads to dying of the cell content. Sclerenchyma is thus usually a dead support tissue, whose task is mainly to provide support an mechanical strength. Depending on the shape of the cells, stone cells (sclereids) and sclerenchyma fibers are distinguished.

Silverberry and the universe

A prepared slide of Silverberry scaly hair is often found in microscopy starters packages for amateurs. The beautiful colors and shapes do well under the microscope.

Smell at a distance

The female silk worm moth (Bombyx mori) makes the pheromone bombykol in a special organ in her abdomen. When she is prepared to mate she releases this to attract males. A male silk worm moth has two long antennas that are very sensitive to the odor of the female. One single molecule is enough to cause a reaction in the sensory cells on the male's antenna. In this way he can locate the female. Even at a distance of 10 kilometers, he can still smell her!

Surface structures easily revealed

As it is known, revealing the surface structure of minerals and fossils can be done by making an ultra-thin section or an acetate peel. An ultra-thin section is a thin slice of a mineral or fossil mounted on a glass slide and viewed under a microscope. Preparing thin sections produces excellently detailed images, but the techniques are relatively difficult and can require expensive equipment. Making acetate peels is much easier and much cheaper.

Acetate peels are made by polishing a surface, etching it with acid to give it some relief, and then chemically melting a piece of acetate film onto that surface with the

Muscovite under polarization microscope

Muscovite has an anisotropic crystal structure, with two optical axis and a negative optical sign. The images and video taken with a polarization microscope with crossed polarizers and the Bertrand lens in place, are showing interference images (without lambda filter) in the plane perpendicular to the bisector between the two optical axes.To obtain these images, a thin slice of muscovite was split off from the crystal and taken for examination. Light entering this slice of crystal, produces the typical interference images for this type of crystal.

Click here for more information about Muscovite Mineral.

Basics of Light Microscopy: Incident Light Microscopy for opaque samples (I)

A closer look on Incident Light Microscopy reveals a new and noticeable fact. In a compound microscope for opaque samples, the objective plays two roles. First, like in a Transmitted light setup the objective is part of the imaging process. Quality and performance of the objective are essential elements to get reliable and “close-to-truth” results. 

Secondly, the objective additionally is part of the illumination system. Light from the lamp house passes the illumination axis and is deflected by a 45° orientated semi-transparent mirror. Sent through the objective, the light is reflected by the sample surface and brings back sample information to the eyepieces/camera. For a beginner it is difficult to accept that both illumination and imaging processes do not interfere visually. 

A pest on grapes

Uncinula necator or powdery mildew, a basidiomycete, is a pest on grapes. Its septate hyphae forms a mycelium on the surface of the leaves similar to a spider web. Special hyphal branches, the haustoria, penetrate the host cells to absorb food substances, thereby weakening the grape and reducing the harvest.

A medicinal parasite

Mistletoe (Viscum album), sinkers in host tissue, longitudinal.

The evergreen, spherical shrub of about 1 m in diameter grows on different trees. As a semi-parasite the mistletoe assimilates with its leaf green. The sinkers of the mistletoe penetrate deep into the wood body of the host plants and withdraw only water and mineral salts from the host, but this causes the part above the infestation site to suffer. The opposite, oblong-ovate leaves evaporate only a little water due to their leathery texture.

Computer chips out of sand

Sand is very rich in the element silicon. This substance can have a very pure grid form, which gives interesting electrical properties. Such a grid consists of almost only silicon atoms. Some of these atoms can be replaced by boron or phosphorus, resulting in semiconductors or transistors in the grid.

Just another worm

Tubifex tubifex, is a ringworm from the Tubificidae family. The scientific name of the species was first published for the first time in 1774 by Müller. It inhabits the sediments of lakes and rivers on several continents.

Cracks in the pipe

The cracks in the austenitic stainless steel sample on the picture below are most likely a case of Stress Corrosion Cracking (SCC). SCC is the cracking induced from the combined influence of tensile stress and a corrosive environment (such as chlorides). The impact of SCC on a material usually falls between dry cracking and the fatigue threshold of that material. The required tensile stresses may be in the form of directly applied stresses or in the form of residual stresses. The problem itself can be quite complex.

Old but indispensable

A polarization microscope can be used to identify the mineralogical composition of geological materials in order to help reveal their origin and evolution. Some of the properties and techniques used include: refractive index, birefringence, Michel-Lévy interference color chart, extinction angle, conoscopic interference pattern (interference figure), Becke line test, wave plate etc.

Prehistoric nail imprints

On the images, a hand formed pottery fragment from the Michelsberg culture, Middle Neolithic period(4300 - 3500 BC) is shown. The Michelsberg culture is responsible for some of the oldest types of pottery in Europe, which is seen as a typical element of this culture. This pottery is generally found on hilltops, giving the impression of the presence of former fortified settlements. This impression is reinforced by findings of many waste pits with very different content and interruptions in the trenches that are interpreted as gates.

About Polarization

Utilizing the polarization method in light microscopy reveals a specific kind of information about the sample. Applying this contrast method, we less often talk about structure size and shape, resolution power or even a specific staining. In case of transparent samples, polarization contrast in first instance has one subject in mind: the potential BIREFRINGENCE of the sample and its implications on a structural insight.

BIREFRINGENCE is a widespread phenomenon, found in nature as well as in man-made materials. Starch grains, fibers, crystals and minerals, plastic sheets and die cast components, the structural basis is always the same: embedded within an amorphous matrix, structures with an intrinsic geometric pattern cause an impact on the speed of light and its oscillating direction when sent through the sample.

Chemical cristals

A sponge a phoenix?

All sponges possess a remarkable ability to regenerate lost parts. A piece cut from the body of a sponge is capable of growing into a complete sponge. This power of regeneration helps the sponges to repair the damage caused in the harsh environment.

Transition of lava on Mount Etna

Limonite is a mineral consisting of various iron oxides. Limonite is yellow, ochre, brown or blackish colored by iron oxide.

Volcanic rock of Mount Etna can be transformed into Limonite, which is called like that because of its yellow brownish color. The Limonite is mainly produced by the oxidation of iron containing lava rocks by weathering, facilitated by splitting and pulverizing of the rock because of the penetration of the roots of vegetation enabling oxygen and humidity to enter.

Algae with an eye

Euglena species are often abundant in calm waters, where they can be present in such numbers, that the surface of ponds and ditches can have a green or red color.

Euglena is commonly studied in biology classes because it has both plant (it has chloroplasts and so can photosynthesize) and animal (it moves and can eat) characteristics. Depending on conditions, photosynthesis or eating can predominate. It is a single celled creature with a large flagellum (not visible in this video, see below) that lives in fresh water. It is generally elongate but can change its shape quite dramatically during so-called euglenoid movement. It swims using its flagellum and can orientate itself with respect to gravity and light.

Wood Collectors?

Wood Collectors primarily collect samples of plants from the group of seed plants, Spermatophytes. This can be either softwood (Gymnosperms) and hardwood (Angiosperms)

Wood however, is composed of various types of tissue, which wood collectors should be able to recognize and name in order to assign a particular species. Tissue which occurs abundantly in one species and is an important feature, can be completely absent in a different species. To see the right features, to name and describe them, is the most important for determination. The recognition of wood types can be done, among others, by the study of micro preparations.

Micro preparations of wood are thin slices of wood of 10-15 microns thick, cut into 3 planes:

a) In the transverse plane for example, the vessels, the distribution of vessels, the type and the distribution of the parenchyma (ground tissue), the number of rays per mm and the thickness of the fiber wall can be seen.