The importance of microscopy as a method to study cells has been overshadowed, to some extent, by methods of molecular biology. However, the microscope remains an important tool. Recent advances in microscopy, particularly the use of fluorescent probes to study cell function in living cells, are bringing microscopy back into the forefront of research in cell biology. Light microscope relies on the simple principle of magnification; an object is magnified in size so that it becomes visible to the observer. There is a limit to the useful magnification that can be achieved in a light microscope because of the limitations in the resolving power of the lenses.

There is a limit in the ability to resolve two separate objects as distinct structures. To view cell structures using light microscope, biologists developed many dyes or strains that either stain whole cell or preferentially stain various organelles within the cell. Like methylene blue stains the nucleus of a cell blue. Various chemicals, including glutaraldehyde or alcohol, are used to cross-link cellular protein and to stabilize cells more or less permanently. Such techniques will be used in cell biology course. For past three or four decades several techniques have enhanced the effectiveness of the light microscopy. It includes phase contrast microscopy, Nomarski differential interference contrast microscopy and Hoffman Modulation Contrast microscopy. These allow cell biologist to examine structures in the living cell without fixing the cell or using staining agents.

The advantages of contrasting enhancing microscopy will become apparent during examination of cells in the laboratory. In addition to light microscopy, fluorescence microscopy has become an important research tool. Cells have complex interactions with the surrounding environment. Whether it is the external world of a single celled organism or the other cells of a multi-cellular organism, a complex web of interactions is present. Study of the mechanisms by which cells respond appropriately to their environments is a major part of cell biology research and often such studies involve what is called signal transduction. For example, a hormone such as insulin interacting with the surface of a cell can result in the altered behavior of hundreds of molecular components inside the cells.

This sort of complex and finely tuned cell response to an external signal is required for normal metabolism and to prevent metabolic disorders like Type II Diabetes Mellitus. Cells of a multi-cellular organism have the same genetic material in every cell, yet, there are over 200 types of cell in the body that are different shapes, sizes and carry out very different functions. ALL of these cells were developed from one special cell called zygote. The study of how the many cell types develop during embryonic development is a branch of Biology that is heavily dependent on the use of microscopy. Much of the control of cell differentiation is at the level of the control of gene transcription the control of which mRNA are made. Muscle cells make muscle proteins and nerve cells make brain proteins. Geneticists, molecular biologists and cell biologists are working to discover the details of how cells specialize to accomplish hundreds of functions from muscle contraction to memory storage.

With the aid of microscope the existence of microorganisms are proven since bacteria were too small to be seen by the naked eye.It took the microscope to expose their tiny world and that instrument has been linked to microbiology since then. In 1664, Robert Hooke devised a compound microscope and used it to observe fleas, sponges, bird feathers, plants and molds. Several years later Anton van Leeuwenhoek, a fabric merchant and amateur scientist became very clever at grinding glass lenses to make microscope. By peering through microscope he observed tiny organisms. Microorganisms benefit to society by cycling organic and inorganic matter into molecules needed for life and detoxifying discarded wastes. It served as microscopic factories for the production of cheeses, alcohol and antibiotics.

Microorganisms have also engineered to produce a wide variety of products for our benefit through the emergence of biotechnology. However, it inflicted great distress to human, animal, and plant populations through disease, spoilage of crops, foods and degradation of man-made structures. Recently microorganisms have been used for terrorist weapon. Microbes cause disease in humans which include Influenza virus, West Nile virus, Staphylococcus aureus and Streptococcus pneumoniae. Surprisingly, many diseases were previously thought to have only behavioral or genetic components have been found to involve microorganisms. The clearest case is that of ulcers, which was long thought to be caused by stress and poor diet. However the causative agent is actually a bacterium, Helicobacter pylori, and many ulcers can be cured with appropriate antibiotics. Other non-infectious diseases such as heart disease, stroke and some autoimmune diseases also suggest a microbial component that triggers the illness.

Some pathogenic microbes have been controlled through the use of antibiotics are beginning to develop drug resistance and therefore reemerge as serious threats in the industrialized world as well as developing nations. Tuberculosis is an illness that was on the decline until the middle 80s. It has recently become more of a problem due to drug resistance and higher population of immunosuppressed individuals. Staphylococcus aureus strains are emerging that are resistant to many of the antibiotics that were previously effective against them. Staphylococcus infections are of great concern in the hospital settings around the world.

The first thing you will notice as you try to peep them through microscope is the numerous bubbles which looks like surrounded by tiny glass beads. Do not be impatient if you think nothing extra ordinary transpire in your sample.Wait for a while until you notice a general streaming movement. Focus on the outer rim of an air bubble and switch to a higher magnification.You will see each yeast cells, looking like a millions of plump or transparent rice grains, surging and multiplying. Concentrate on one spot so you can observe buds forming on the parent cells, breaking off and floating away on their own.This how yeast cells reproduce.

Finding the Microbes

If you want to observe how microbes go on with their lives, you will have to provide these microorganisms some liquid place to live. With the use of a jar that has a screw top, get a sample preferably from stagnant puddles and ponds.It would be interesting if you added some bits of water plants and bottom mud. Fish tank and water from the flower vase would also be a good source of your sample. These two will give you some promising results.After you collect water from different sources, label the jars to help you remember where each sample came from.

The most important thing you need to do is to always wash your hands thoroughly after handling some water infected by microbes.Though some of the microbes are harmless, others are equally dangerous too. When preparing a slide, do not rub your eyes or touch your mouth and nose.And most of all, avoid eating while you are dealing with the specimen with microbes.

We are familiar with pollen grains. We know that they help the plants to reproduce. It is even called an agent of pollination. But how it really works closely? Pollen is a powdery-looking substance. It is often presents to the flowering plants. Pollen usually serves as a means of reproduction among the plants specifically those that are considered flowering plants. If you look at the center of a mature flower, you would always find its reproductive organ. The first thing you could see is the pistil (female organ). The one that surrounds it is the stamen (which is the male organ). At the end of the stamen, you will see is the anthers. It is like a bag that contains pollen. Touch the anthers and you will find some of the pollen sticking to your finger. Flowers, attractive as they are as a part of a plant, invite bees and insects to come and drink their nectar. As they come in contact with the flower, both their legs and furry bodies touch with the pollen. The result, pollen sticks to them. Now, what compose of pollen that it makes stick to any object that comes contact with it? If you examine the pollen under the microscope, you will understand why it sticks to every thing it touches. The surfaces of the grains are cleverly designed to make them cling. Some flower pollens have burrs; others may be ridged or spiked.

The Seeds

After the pollination, the flower fades. On the other hand, the fruit, which contains seed, develops inside the pistil. Usually after the fruit has been picked and eaten, the seed is dropped. By chance, it may enter the soil and start a new plant. If you observed this scenario under the microscope, you will find that inside seed a new plant, waiting to emerge. For example, get a maple seed or lima beans. Soak their dry seeds in water overnight or put them on a bed of wet cotton and wait till they start to sprout. You can open the softened seed with a needle and lay it down flat on a slide for observation.

The Spores

There are plants that do not contain flowers or seeds. They do not have pollen to start their reproduction. The exact example of this type of plants is the ferns. But how do they reproduce? They have spores. The spores are the reproductive bodies of these non-flowering plants. Spores drop from the plants the minute they are ripe and then, they would create another plant again. That is how they reproduce.

Plants that have Spores

The ferns are considered non-flowering plants and they are interesting to observe under the microscope. Generally, ferns grow in moist, shady places and can also grow in pot. The back of the fronds, the leaves of ferns, you would find that it is composed of a regular pattern of usually brown dots on the lower side. These are the spores.Take note that the particular frond depends on what season you picked them. For instance, try to pick a frond during early summer and place it between a slide and a cover slip. Under the microscope, you will notice that the cluster of spores resembles orange and brown grapes. Later, these spores will turn like thick, ropy coils of dark rings. As the coils finally open up, closely packed brown spores begin to spill out and thus, a new plant will start where the spores fall.

Euglena and Diatoms

Generally, algae are considered to be plants but some of them are energetic swimmers. The green scum that we usually see in the ditches and ponds are caused by Euglena, a small, bright green, spindle-shaped organism that swims by whipping the water with its flagellum. Euglena puzzled the biologist for a long time. Their dilemma is whether to classify euglena as plant or animal. In a way it is both. Euglena contains chlorophyll, which enable this organism to produce its own food. However, the minute it has to go without light for any length of time, the green color disappears. On the contrary, euglena stays alive by absorbing ready-made nutrition in the form of decaying matter in the water, which it absorbs through its skin. Botanist considered Euglena as green algae but the zoologists classify this organism as flagellate protozoa. There is another type of algae called diatoms. These are yellow green algae which occurring abundantly in fresh waters, oceans, and also in soil. Diatoms look as if they were in glass boxes. Their translucent shells come in variety of shapes, and others in delicate colors. When diatoms are magnified, they catch and reflect the light like rare and complicated jewels.

During nineteenth century, some microscopists enjoyed the painstaking hobby of collecting diatoms and arranging them on slides in samplers and patterns. Take note, one slide can hold hundreds of diatoms. Some of these intricate slides have been preserved and are valuable collectors items today. Diatoms are not only beautiful examples of nature great variety of design. Deposits of these shells resulting from centuries of growth are called diatomaceous earth. This substance forms the basis of many commercial applications.The Uses of Algae – Algae are considered as the most important photosynthesizing organisms on earth. They capture more the energy from the sun and produce more oxygen than all plants combined. Algae form the foundation of most aquatic food webs, which support an abundance of animals.

Algae as Food – Through the years, human ingenuity has found many uses in algae. Algae provide food for the people. More than 150 species of algae are commercially important food sources, and over 2 billion dollars of seaweeds is consumed each year by human, mostly in Japan, China, and Korea. The red alga Porphyra, called nori, is the most popular food product. After harvesting, nori is dried, pressed into sheets, and used in soups, sauces, sushi, and condiments. Algae are considered nutritious because of their high protein content and high concentrations of minerals, trace elements, and vitamins. The high iodine content of many edible algae may contribute to the low rates of goiter observed in countries where people frequently eat algae. Algae in Livestock – In coastal areas of North America and Europe, seaweeds are fed to farm animals as a food supplement.

Cyanobacteria species that are high in protein are grown commercially in ponds and used mostly as a health food and cattle dietary supplement. Seaweeds also are applied to soils as a fertilizer and soil conditioner, as their high concentrations of potassium and trace elements improve crop production. Some species of cyanobacteria can turn atmospheric nitrogen into ammonia, a form that can then be used by plants as a nutrient. Farmers in tropical countries grow cyanobacteria in their flooded rice paddies to provide more nitrogen to the rice, increasing productivity as much as tenfold.
Algae as thickening agents – Seaweeds are a critical source of three chemical extracts used extensively in the food, Pharmaceutical, textile and cosmetics industries. Brown algae yield alginic acid, which is used to stabilize emulsions and suspensions; it is found in products such as syrup, ice cream, and paint. Different species of red algae provide agar and carrageenan, which are used for the preparation of various gels used in scientific research.

Agar is also used in the food industry to stabilize pie fillings and preserved canned meat and fish. Carrageenan is also used as a thickening and stabilizing agent in products such as puddings, syrup, and shampoos.Algae in medical world – Algae have been used for centuries, especially in Asian countries, for their purported powers to cure or prevent illness as varied as cough, gout, gallstones, goiter, hypertension, and diarrhea. Recently, algae have been surveyed for anticancer compounds, with several cyanobacteria appearing to contain promising candidates. Diatoms also have been used in forensic medicine, as their presence in the lungs can indicate a person died due to drowning.

Algae in Ecosystem – Algae serve also as environmental problems in aquatic ecosystems. Because they grow quickly and are sensitive to changing environmental conditions, algae are often among the first organisms to respond to changes. For instance, depletion of diatom community in Florida everglades provided strong evidence of phosphorus-related changes in this unique ecosystem. Algal blooms may deplete oxygen concentrations in water and smother fish and plant life, as well as prevent light penetration for algae at lower depths, preventing photosynthesis.

Protozoa is the diverse assemblage of organisms that carry out all of their life functions within the confines of a single, complex eukaryotic cell. Proto means first and zoa mean animals. But these basic animals are not as simple as the name would lead one to believe. Nature has given their jellylike bodies many variations. There are even protozoa that are bullet-shaped, pointed, round as ball, eel-shaped, or even trumpet shaped.

Groups of Protozoa

There are different groups of protozoa. Some protozoa zoom through the water as fast as torpedoes, others hover like bees over a flower, still some of protozoa jerk or hop like fleas. Biologist has divided protozoa into four classes, based on their different means of locomotion.

A. Ciliates – this group of protozoa equipped with eyelash like hairs called cilia, which could wave quickly back and forth like flexible oars.
B. Flagellates – this group, swim through their whip like tails or flagella.
C. Pseudopodia – they move by sticking out projections and then letting the rest of their bodies follow. The projections look somewhat like shapeless feet, thus, this group is called Pseudopodia which come from two Greek words, pseudo and pod meaning false foot.
D. Sporozoa – this group of protozoa do not have an organ of locomotion. Although they are not fun to watch under the microscope, scientists have interest on them because most of the sporozoa are parasites that could actually harm the larger life forms, including humans. One of the diseases that this group caused is the malaria.

Although protozoa are frequently overlooked, this group of microorganism plays an important role in many communities where they occupy a range of tropic levels. As predator upon unicellular or filamentous algae, bacteria, and micro fungi, protozoa play a role both as herbivores and as consumers in the decomposer link of the food chain. As components of the micro and meiofauna, protozoa are an important food source for micro invertebrates. Thus, the ecological role of protozoa in the transfer of bacterial and algal production to successive tropic levels is important.

Even our bodies are home to many different kinds of bacteria. Our lives are closely intertwined with theirs, and the health of our planet depends very much on their activities.Bacteria inhabited Earth long before human beings or other living things appeared. The earliest bacteria that scientist have discovered, in fossil remains in rocks, probably lived around 3.5 billion years ago.These early bacteria inhabited a harsh world: It was extremely hot, with high levels of ultra violet radiation from the sun and with no oxygen to breathe.Before the development of the microscope, some people speculated that small, invisible particles caused diseases and fermentations. But not until the late 1600s did anyone actually see bacteria. In the 1670, Dutch lens maker Anton van Leeuwenhoek first saw what he called “wee animalcules” under his single-lens microscopes.

Leeuwenhoek noticed cells of different shapes within a variety of specimens, including scrapings from his teeth and rainwater from gutter. His findings laid the foundation of microbiology.The microscope was improved over the following centuries, but bacteria still appeared as tiny objects, even with magnifications at 1, 000 times. In the 1930s, the first electron microscopes were developed.Using beams of electrons instead of light, these microscopes could magnify objects at least 200 times more than light microscopes could. With magnifications of 200, 000 times actual size, it became possible to see structures within bacteria cells in detail.

The Flower

We all know that the most attractive parts of the plant is the flower. It is the most eye-catching part of every plant. Let us dissect the plant by starting with the flower. Get a piece of petal of flower. May it be small or big petal, it does not matter. But it would be better if you get a bright colored petal because this one will present a more amazing sight compared to the white one. Cut a piece of petal and mount it between two slides. Do not tilt your microscope stage because the cover slip that holds your petal might fall off. Since the cover slip is thin, it will give you a better view the minute you put your sample under the microscope. Now, depending on the color of the petal, a dewy field of pink, gold, or blue pearls will unfolds on your sight. These are the cells. If you use a petal that is fresh, the cells appear plumply filled water, making them soft and springy. If you want to see the cell dry and flat, look the slide after few days.

How the Water Works in Plants

We all know that without water, plants will not survive. The latter is the most essential factor that keeps all living things alive in this world. Water is important in life cycle of every living thing.We often, pour water on our plants. But it would be interesting if you could see how it works the minute you put it on the plant. How does water rise from the wet soil and travel all through the plant? Under the microscope you can follow the channels it takes, from the root through the stalk to the leaves and flowers.Try to get any plants you want from the ground. May it be weeds or wildflowers. Cut samples of the different parts of the plant, from the roots to the flower, and mount them on slides. If you observe the tiny root hairs trailing from the roots, that is where the water begins to travel. The root hairs are narrow tubes that search out moisture in the soil and draw it in. This is they usually call the capillary action in which the thin channels enable water to travel upward.

Slice very thin cross sections of the stalk with the use of blade. Place a slice on a slide without a cover slip. You will find yourself looking straight down the bundles of tubes that bring water to the upper plant, like that of the water pipes. Notice the closely spaced green cells of the outer rim and the honeycomb of large, colorless cells forming the core of stalk.Finally, prepare a slide from part of a leaf. If the leaf of a plant is too thick for light to shine through, use clover or some other much smaller, thin leaf. If you see, the small and large veins making up the skeleton of a leaf, are the main water ways by which water and nutrients are carried to the cells. The rest of the nourishment comes from the sun.

Bacteria inhabited Earth long before human beings or other living things appeared. The earliest bacteria that scientist have discovered, in fossil remains in rocks, probably lived around 3.5 billion years ago.These early bacteria inhabited a harsh world: It was extremely hot, with high levels of ultra violet radiation from the sun and with no oxygen to breathe.Before the development of the microscope, some people speculated that small, invisible particles caused diseases and fermentations. But not until the late 1600s did anyone actually see bacteria. In the 1670, Dutch lens maker Anton van Leeuwenhoek first saw what he called “wee animalcules” under his single-lens microscopes.

Leeuwenhoek noticed cells of different shapes within a variety of specimens, including scrapings from his teeth and rainwater from gutter. His findings laid the foundation of microbiology.The microscope was improved over the following centuries, but bacteria still appeared as tiny objects, even with magnifications at 1, 000 times. In the 1930s, the first electron microscopes were developed.Using beams of electrons instead of light, these microscopes could magnify objects at least 200 times more than light microscopes could. With magnifications of 200, 000 times actual size, it became possible to see structures within bacteria cells in detail.