...your lab class. Please be aware that you need to go online to answer prelab question #3. Goals of this Lab Exercise After completing this lab exercise you should be able to..... 1. Identify the parts of a compound light microscope and use a microscope to competently examine biological samples 2. Determine the diameter of the field of view for the various objectives of a microscope 3. Accurately sketch, describe and cite the major functions of the structures and organelles of the cells examined in this lab exercise 4. Estimate the size of specimens viewed with a microscope. The Microscope The microscope is one of the principal tools of the biologist. Without the microscope, many of the great discoveries of biology would never have been made. The light compound microscope, illustrated in Figure 1, is the type of microscope most commonly used. Proper, comfortable use of the instrument demands practice. The practice afforded you in this exercise depends upon familiarity with the parts of the microscope and with their interactions. Figure 1. A typical compound light microscope used in many biology labs. 1 Lab 2 Biology 100 Note each of the following features of the microscope and there individual uses to allow you to take full advantage of the use of a microscope. Ocular or Eyepiece—contains a lens that magnifies the specimen (usually 10x) Revolving Nosepiece—used to change...
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...An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. Because the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, the electron microscope has a higher resolving power than a light microscope and can reveal the structure of smaller objects. Electron microscopes are used to investigate the ultrastructure of a wide range of biological and inorganic specimens including microorganisms, cells, large molecules, biopsy samples, metals and crystals. Modern electron microscopes produce electron micrographs using specialized digital cameras and frame grabbers to capture the image [216] The original form of electron microscope, TEM uses a high voltage...
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...[pic] HISTORY OF MICROSCOPE Oddly enough, the compound microscope was invented before the single lens microscope. But the instruments were not very good to start with and much more could be seen with very small lenses of short focal length. In about 1597 two Dutch eyeglass makers, Zaccharias Janssen and his son Hans were experimenting with lenses in a tube. They observed that nearby objects viewed through two lenses in line were magnified. Their device was the first compound microscope. However, their lenses were rather large and the magnification obtained was only about 10X. Galileo also designed a compound microscope, but it was only useful for reflected light. Robert Hooke built the first useable British compound microscope in about 1655. The single lens microscopes made by a Dutch amateur lens grinder Antonie van Leeuwenhoek were far superior to the early compound instruments. Van Leeuwenhoek, in about 1670, developed a method for grinding very small glass lenses. They were tiny, of the order of a millimeter in diameter, and could magnify several hundred times. Mounted in a brass plate these lenses could use transmitted light to image objects in a drop of water on the end of a metal pin. Screws were used to move the pin and focus the specimen. Van Leeuwenhoek was probably influenced by Robert Hooke’s Micrographia (1665) which he might have seen when he visited London in about 1668. Amongst his vast number of discoveries were bacteria, sperm, blood cells and a...
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...The microscope is an instrument permitting the visual observation of small objects or object details usually indistinguishable to the naked eye. There are two types of microscopes: Light microscopes, and electron microscopes. Light microscopes utilizes optical lenses to form the image by controlling the light beam for illuminating the sample. An electron microscope is a type of microscope that uses an electron particle beam for illuminating a sample and create a greatly enlarged image. In this laboratory session we observed different specimens to be familiar with the use of microscopic techniques and functions of its components. Pre lab questions: Electron microscopy uses a beam of electrons as an energy source. A stereoscopic dissecting microscope is used to view large objects. Reflected light microscopy uses top-down lighting to illuminate the specimen and the light is reflected back from the specimen to the viewer. Transmitted light microscopy uses bottom-up illumination where the light is transmitted through the specimen to the viewer. Stereomicroscope uses reflected light to be focused by lenses from...
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...AFM Tutorial Within the past decade, a family of powerful surface imaging techniques, known collectively as scanned probe microscopy (SPM), has developed in the wake of the invention of the scanning tunneling microscope (STM). Each scanned probe technique relies on a very sharp probe positioned within a few nanometers above the surface of interest. Some combination of probe and/or substrate positioning is required to provide sub-nm-resolution, three-dimensional motion of the probe relative to the substrate. When the probe translates laterally (horizontally) relative to the sample, any change in the height of the surface causes the detected probe signal to change. In general, if the probe signal decreases, this means that the point on the surface directly beneath the probe is farther from the probe than the previous point was. Conversely, if the probe signal increases, then the point on the surface is closer to the probe than the previous point. The electronic circuit that controls the vertical position of the probe relative to the sample uses these changes in the probe signal as sensory feedback to decide which direction (up or down) to move the probe to maintain a constant probe signal. When the probe signal decreases, the circuit realizes that the surface is now farther away, so it moves the probe down until the signal increases to the same level that was measured at the previous point. Similarly, the circuit responds to increases in probe signal by moving the probe up, away...
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...discoloured and cloudy, while the broth in the curved-neck flask had not changed. | 5. He concluded that germs in the air were able to fall unobstructed down the straight-necked flask and contaminate the broth. The other flask, however, trapped germs in its curved neck, preventing them from reaching the broth, which never changed colour or became cloudy. | 6. If spontaneous generation had been a real phenomenon, Pasteur argued, the broth in the curved-neck flask would have eventually become reinfected because the germs would have spontaneously generated. But the curved-neck flask never became infected, indicating that the germs could only come from other germs A compound light microscope is a microscope with more than one lens and its own light source. In this type of microscope, there are ocular lenses in the binocular eyepieces and objective lenses in a rotating nosepiece closer to the...
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...Microscope Familiarization Purpose: The purpose of this lab is to help familiarize myself with the microscope. Problem: What are the appropriate procedures when using the microscope? Materials: Computer, Paper, Pen, Laboratory Manual, Thread, Hair, Microscope, Slide, Slide Cover, Small Glass Bottle, Dropper, and water. Procedure: I started by logging into the computer and completing the training module online. Then I went to the cart and brought the microscope over to my work area, making sure to carry the microscope by the arm and base. I uncovered and plugged in the microscope. I then went back to the cart and got a slide and slide cover, as well as a small glass bottle and dropper. I filled the small glass bottle with water and took everything back to my work area. I wrote a letter e on a piece of paper with a pen, pulled a strand of hair from my head and pulled a string off of my jacket. Then I turned on the microscope, prepared my slide and proceeded to look at each object under the microscope. Data: If the slide was too close or too far from the lens than you will not be able to see the specimen. The larger the magnification on the microscope the more detail that can be seen. The course and fine adjustment knobs move the slide up and down to help focus the specimen on the slide. The mechanical stage controls move the slide left and right, and forward and backwards. Findings: While observing the hair under the microscope I noticed that it is not smooth. The hair actually...
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...Lecture 1: Syllabus II. Reading Assignments for Chapter 1 A. Lecture 2: 1. Define Microbiology & Microorganisms 2. sec 1-1: pp. 1-4: Members of the microbial world B. Lecture 3: 3. Why is microbiology important? 4. Integrated content of Sec 1.4, pp. 17-19 C. Self-Learning: History of Microbiology 5. Sec1.3, pp. 11-16 please read! III. Chapter 2: All sections will be covered from this chapter but keep in mind, BIOL201 emphasizes ALL microscopes; I will focus on the bright-field light microscope, discuss staining, and then provide a brief overview of other types of microscopes. D. Order of content in lecture: 2.1, 2.2 Light Microscopes emphasizing bright-field microscopy up to p. 26, Staining: 2.3 p. 31-34; Sec 2.2; Other microscopes in sec 2-2 p. 26-31; sec 2.4-2.5. E. This will be covered 8/26, 8/28, and part of 9/2. F. Have a general idea on how all of the microscopes work that I do not cover in depth. My emphasis will be on: Brightfield, fluorescence, and electron microscopy. Cell Structure- Ideal Lecture order: (Chapter 3 &4) DATE | Text Chapter | Lecture Topic | | | Prokaryotic Cell Structure & Function. Ch 3 discusses the structure of Bacteria while Ch 4 discusses Archaea. Note: Ch. 5- Eukaryotic Cell Structure was covered in Biol-201. I will not cover this information but I will hold you responsible for this material. | 9/2 (W) | Ch. 3 &...
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...The most interesting thing I observed in today’s microscope lab was that I was able to view algae from a sample of pond water. The total magnification which I made the observation was 450. Been able to see algae just with the sample of pond water is amazing because whenever I see pond water I never think about what it beholds I just thought of it as water and nothing spectacular. 2. In the plant cell I observed the chloroplast organelle. My observations for the chloroplast organelle was that the shape was a circle and very tiny. I also I learned that the function of the chloroplast organelle is to conduct photosynthesis. In the animal cell I observed the nucleus. My observations for the nucleus was that the shape was a oval. When you look through the microscope it looks like a nucleus inside of the nucleus. I also I learned that the animal cell of the nucleus is to hold genetic code (DNA). 3. If I looked at bacterial cells with the microscope, I would expect to see neither one. Due to bacteria is a prokaryotic cell. Though, bacteria cells is a living...
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...Compound Microscope Parts A high power or compound microscope achieves higher levels of magnification than a stereo or low power microscope. It is used to view smaller specimens such as cell structures which cannot be seen at lower levels of magnification. Essentially, a compound microscope consists of structural and optical components. However, within these two basic systems, there are some essential components that every microscopist should know and understand. These key microscope parts are illustrated and explained below. STRUCTURAL COMPONENTS The three basic, structural components of a compound microscope are the head, base and arm. •Head/Body houses the optical parts in the upper part of the microscope •Base of the microscope supports the microscope and houses the illuminator •Arm connects to the base and supports the microscope head. It is also used to carry the microscope. When carrying a compound microscope always take care to lift it by both the arm and base, simultaneously. Ocular with Pointer eyepiece which magnifies image projected by objective Body Tube maintains the correct distance between the eyepiece and the objectives (usually 25 cm) Arm supports the body tube and is used to carry the microscope Coarse Adjustment a knob that makes large adjustments to the focus Fine Adjustment a knob that makes small adjustments to the focus Nosepiece holds the objectives and can be rotated to change the magnification Objective Lenses Adjustable...
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...TASK 1 Comparing light and electron microscope Note:- A microscope is an instrument used for viewing a tiny object that cannot be seen with our naked eyes. The microscope is an important instrument found in the laboratory. We have two types of microscope. Light Microscope and Electron Microscope. The light Microscope is one which can be illuminated by light while an electron microscope is one which can be illuminated by electron. Electron microscope is expensive and not portable compared to the light microscope. The Electron microscope is then of two types. We have the Scanning Electron microscope and the Transmission Electron microscope. Features Light Microscope Electron Microscope Comments Cell Components Seen Animal Cell:- Nucleus, Nucleolus...
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...on using the Microscope: The purpose for my manual topic is showing on how to use the microscope and also the assembly of a microscope when is taken out of the box. The very first and most important fact is picking a title that is clear on what it is going to explain. Also picking a readable font is really important for making the audience want to read the manual. At the beginning of my manual, I will have the table of content, which is the most basic part that a manual should have. The first part of my table content will include safety, which in my opinion is the most important fact using a product, although there is not that much peril utilizing a microscope. After safety, I will have the introduction, which will provide brief information about different types of microscopes and how they differ in terms of the purpose they are used. I also will give brief descriptions about what a microscope is and what is exactly used for; assuming part of the audience doesn’t know that much about microscopes. I will explain about parts of the microscope and what function they have; parts such as eyepiece, objective lens, focus adjustment knob, stand column, and etc. I will put a figure showing each part so the audience has a better understanding of the microscope. I will mention all the parts that are included in the box and all the extra equipment needed for the assembly of the microscope such as screwdriver. After all that, I will start with how to operate the microscope with a quick...
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...M2D1: Microscopy and Differential Staining 1. What are the advantages and disadvantages of the different types of light and electron microscopes discussed in Chapter 3 that are used to study microorganisms? Focus your response in terms of the following parameters: o Range of magnification o Resolving ability o Sample preparation o Possible states of sample (e.g. whole organism, part of, living, non-living, etc Compound Light microscopes magnification is 2000X. Resolution of about 0.2μm. Can only see very small specimens and specimens are stained. Darkfield – used to study live microorganisms that cannot be stained or staining distorts the image or they are invisible using the normal light microscope. Phase-Contrast – in living microorganisms, this scope allows you to see detailed internal structures, plus you do not have to fix or stain the microbes. Differential Interference Contrast (DIC) – instead of one beam of light, 2 beams are used. Image looks almost 3-dimensional and is brightly colored. Fluorescence – used mainly as a diagnostic technique. Stained with fluorochromes and viewed with an ultraviolent light. Confocal – makes 3-dimensional images using a computer. Able to see entire cells and their components. Two-Photon – living cells can be seen up to 1mm (1000um) deep in tissues. Can also track, in real time, the activity of cells. Scanning Acoustic – living cells that are attached to cancer cells, artery plaque and biofilms can be seen through...
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...was a basket-maker, while his mother's family were brewers. Antony was educated as a child in a school in the town of Warmond, then lived with his uncle at Benthuizen; in 1648 he was apprenticed in a linen-draper's shop. Around 1654 he returned to Delft, where he spent the rest of his life. He set himself up in business as a draper (a fabric merchant); he is also known to have worked as a surveyor, a wine assayer, and as a minor city official. In 1676 he served as the trustee of the estate of the deceased and bankrupt Jan Vermeer, the famous painter, who had had been born in the same year as Leeuwenhoek and is thought to have been a friend of his. And at some time before 1668, Antony van Leeuwenhoek learned to grind lenses, made simple microscopes, and began observing with them. He seems to have been inspired to take up microscopy by having seen a copy of Robert...
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...technique helps in order to study slides with specimen under a microscope. In this skill the specimen ejected along with a drop of liquid (e.g. water) and then it is covered with a cover slip. Unlike permanent mount slides, wet slides cannot be stocked for over a long period of time as the liquid might evaporate and growth of unwanted microorganisms may lead to the contamination of the slide. In order to avoid this contamination and still be able to use the slide for...
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