Ficus carica petiole and Wacker 3A staining

Vascular bundles can be seen very well in these cross-sectional views of a leaf stem of the fig tree, thanks to the Wacker 3A triple staining. This coloring is done with a mixture containing Astra blue, Acriflavin and Acridine red.

We see the vascular bundles that lie in an outer circle, characteristic of (eu)dicotyledonous plants. In monocotyledonous plants, the bundles are irregularly distributed over the cross section. The Xylem vessels lie on the inward side and the Phloem vessels on the outside of the outer circle. Between Xylem and Phloem we see the intravascular Cambium. Vascular bundles are also present in the inner basic Parenchyma.

Due to the good uniform thickness of the coupe and the fine quality of the Moticam S12 camera, the photos could be taken without stacking.

Tempskya, growing millions of years ago

Tempskya is an extinct genus of tree-shaped ferns, the fossils of which have so far only been found in Cretaceous layers. The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic period 145 million years ago to the beginning of the Paleogene period 66 million years ago.

The stem-shaped structure of Tempskya is called "false stem" because it is formed by an entanglement of large numbers of stems and roots. The upward growing stems, which have a diameter of 2.5-10 mm, gave large numbers of roots (diameter about 1 mm) that grew downwards. They formed a felt-like mass around the stems. Because the stems branched regularly, a very solid whole was created. On a cross section of a trunk (see the images) the relatively large stems and the small roots can be seen.

 

The Rose of Jericho ‘a plant full of fire’

The Dutch Society for Microscopy (NGVM) department West, organized a workshop on fluorescence microscopy. An introductory presentation was given on this important application of microscopy. Fluorescence microscopy is used in many different fields, such as in medical science, for example in cytology, but also in other areas such as forensic research, pollen research, mineralogy, etc.

Nettles - The healthy stingers

The plant urtica dioica, more commonly known as the stinging nettle, is a plant many of us are unpleasantly familiar with. The quite fitting name ‘nettle’ comes from the anglo-saxon word ‘noedl’ which means ‘needle’ and the latin ‘urtica’ means ‘to burn’. The plant is found worldwide but was originally native to Europe. At its tallest, the nettle grows to around two meters and are equipped with medium sized leaves. Despite many myths both the stem and the leaves are able to sting you as both are covered in the tiny needle-like structures called trichomes or spicules responsible for the burning sensation you get after contact with the plant.

Myriophyllum beautiful but a nuisance

Myriophyllum or Red stem is a water plant that prefers to take root on the transition from land to water. The stems can grow up to 2 meters long and protrude a few decimetres above the water. Red stem grows particularly well in shallow, warm and nutrient-rich waters. The plant usually roots in shallow riparian zones, but free-floating stems without roots can also survive in nutrient-rich deep water. Red stem is originally from South America.

Myriophyllum was imported for trade in pond and aquarium plants. The plants come into nature because people throw away excess plants in public waters, after which they can spread further.

Protected against harsh conditions

As mentioned in a previous publication, helm grass is what we encounter in the dunes among others in the Netherlands. The Ammophillia arenaria can withstand the salty water and salty sea air. Ammophillia arenaria can be planted on all types of soil, only on clay soil it is best to make the soil poor with masonry sand. The soil must be calcareous.

Chloroplasts - the solar panels of the plant cell

We have known for many years that plants get their energy from the sun. But turning sunlight into usable energy requires some special hardware, and this is where chloroplasts come in. Chloroplasts are microscopic structures present in most plant cells. In fact, they are present in such high numbers that you can see them without a microscope as the green color of plants. The chloroplasts green color is due to the presence of a green pigment called chlorophyll, which absorbs both red and blue lightwaves from the sun and reflects green light giving the pigment its green color. The red and blue sunlight (energy) absorbed by the molecule is then able to drive photosynthesis which happens in the chloroplasts.

Euglena - part plant, part animal

Cells with a nucleus are called true cells, or eukaryotes, which can be further subdivided into kingdoms like plant and animal. Plant cells and animal cells are different in their components and structure, but some organisms does not fit as neatly into these little boxes and can be tricky to place on ‘the tree of life’. One of these is the single celled organism euglena.

Euglena with clearly visible red eyespots

Mysterious crystal growth on tiny crustaceans

Crustaceans form a large group in the animal kingdom, and most are familiar with some of the larger members like crabs, lobsters, and shrimps. But many crustaceans are a lot smaller than those, and make up an important part of the food chain as food for fish and other larger animals. One of these planktonic species is daphnia magna, and with a size of 1.5 to 5 millimeters it is one of the largest in its family and just visible with the naked eye. However, it is not the daphnia itself we will focus on today. But a strange phenomenon that occurs on its body, as well as on a few other tiny crustaceans like it.

Female Daphnia magna carrying the next generation in a cavity.

Stentors - some of the largest single celled organisms in the world

Stentors are trumpet shaped single celled organisms found in freshwater habitats like pods and streams. Due to their shape they are more commonly known as trumpet animalcules. Stentors are some of the largest single celled organism in the world, with the largest species reaching a size of up to two millimeters, and it is therefore possible to spot them in a water sample without a microscope. Stentors are ciliates, which mean that they move and feed with tiny hair-like projections called cilia. They have a large number of these cilia surrounding the mouth which creates a current of water carrying food particles for ingestion. In the opposite end they have a foot which is they use to adhere to a substrate.

Observe the classic trumpet shaped appearance and the clearly visible cilia surrounding the mouth.

Eudorina - a colonial algae

Eudorina is a genus of green freshwater algae. Each eudorina are multicellular colonies consisting of 16, 32 or even 64 individual cells held together by a gelatinous substance made of sugary proteins, or glycoproteins to be a bit more scientific. The individual cells in a colony are not much larger than our blood cells, and the entire colony is about the same size as the width of a human hair. The green color is due to the presence of large chloroplasts inside each cell used for energy production through photosynthesis.

Note the gelatinous transparent matrix surrounding each colony.

Wormwood fluorescence

The photos we see here were taken from a Plescher prepared slide. Plescher fluorescence prepared slides are characterized by a distinctive, three-dimensional, deeply structured honeycomb structure. This is made possible by special, complex, gentle pre-treatment of the hand coupes made of living material that reproduce the sensitive cell contents surprisingly well. The conventional ultra-thin section technology with embedding in paraffin, does not provide the same detailed results. Plescher specimens impress with their specially developed Plescher staining with clarity and gloss, differentiated on a deep black background at 460 - 490 nm excitation wavelength. They are therefore generally ideal for photo stacking.

Hydra - The immortal monster of the micro world

A hydra might look a bit like a miniature octopus, but it is actually a lot closer related to jellyfish. It is relatively common in both tropical and temperate regions where it can be found in slow flowing streams, ponds and other freshwater habitats. At one end the animal has one to 12 tentacles which all have their origin around the mouth. In the opposite end is a ‘foot’ allowing the hydra to attach to a substrate. The body can measure up to 10 mm when fully grown and stretched.

Note the small buddig of a new hydra on the lower side.

Yeast - The helpful and harmful organism

Yeast is a big part of our lives and human culture in general. It is involved in everything from alcohol production and bread making, to scientific research and probiotics. However, some yeasts can also be pathogenic and cause human infections.

Yeasts are unicellular fungi that mainly metabolism sugars for energy. They are very common in the wild where they can be found on the skins of fruit and other sugar-rich places like cereal grain crops. Even though yeast plays a huge role in many aspects of our everyday lives, most species are only about 4 microns in diameter, which is about half the size of our red blood cells. in comparison, a single human hair is roughly 80 microns thick.

Tardigrades - Some of the toughest, and smallest, animals on earth!

Tardigrades are some of the smallest animals on the planet. Most are around 500 microns (half a millimeter), but newly hatched tardigrades can be 10 times smaller than that. And the biggest ones only reach about a 1.5 millimeters. Tardigrades are more commonly known as water bears. This is because of their bear like appearance when they waddle around looking for food. But, unlike a bear, tardigrades have eight legs which all end in several claw-like toes. Most tardigrades are herbivores and eat thing like algae and other plant material. However, not all tardigrades are grazers, some are hunters and eat things like bacteria, single celled organisms, rotifers and even other tardigrades.

Living tardigrade from the genus Ramazzottius.

Tardigrade from the genus Milnesium mounted in hoyer's medium.

Skin Cells

The skin cover the entire body and is our largest organ. It functions to protect the internal organs from mechanical, thermal, and chemical exposure as well as prevent evaporation of body liquids and of course also act as a barrier for pathogens. The outermost layer of the skin is called the epidermis. This layer varies in thickness depending on the location, but in general it is about 0.2 mm - 0.5 mm, or 200-500 microns thick. The epidermis can be subdivided into five (actually six) individual layers all made up mostly of skin cells, called keratinocytes. In fact 90-95% of the cells in the epidermis are keratinocytes.

Volvox bloom

Volvox is a popular alga among microscopists because of the beautiful images it produces under the microscope. The volvox in the video was unexpectedly found in a pool in Eindhoven, the Netherlands in early November 2019. There were so many of these species present that one could speak of a bloom.

The green alga Volvox is a colony of cells that have started to work together. Some cells catch the light, others provide movement or reproduction. They have become so dependent on each other that you can speak of a multicellular organism.

Colorful microscopic crystals

Vitamin C (ascorbic acid) | Motic BA310E 4X | Moticam Pro S5 Lite | © My Microscopic World

A crystal is a solid where the individual molecules are arranged in a highly ordered three-dimensional structure like we see in grains of sugar and table salt. This is compared to when a substance is dissolved in a liquid and all the individual molecules are floating randomly around. If a liquid with a crystallizable substance is left to evaporate. The individual molecules will rearrange themselves and get bound to one another in a crystalline structure. Depending on which substance it is, both the micro- and macroscopic crystal structure will vary greatly.

Allergic dermatitis in cats

When a cat comes into contact with an allergen, their body can react causing itching and inflammation. More severe cases of allergic dermatitis are easily recognized, while other may have very subtle signs and symptoms. That is why it is important to take a biopsy to make this sure and to investigate that it is not another ailment.

Primitive, but unique

Ferns are perhaps very old plants, but they are unique in their kind. They already occur in several hundred million year old fossils. After all, it was the first plant with roots and a real vascular system. In this way the ferns managed to extract water from the ground and use it for their further development. Because of the branches of the vessels it was also possible to get the water into the tops of the feathers or leaves. Ferns do not carry flowers. They therefore do not propagate with seeds, caused by fertilization of pistils with pollen through bees, beetles, birds, wind or otherwise.