...Phase Contrast Microscopy Phase Contrast Microscopy, first described in 1934 by Dutch physicist Frits Zernike, is a contrast-enhancing optical technique that can be utilized to produce high-contrast images of transparent specimens, such as living cells (usually in culture), microorganisms, thin tissue slices, lithographic patterns, fibers, latex dispersions, glass fragments, and subcellular particles (including nuclei and other organelles). In effect, the phase contrast technique employs an optical mechanism to translate minute variations in phase into corresponding changes in amplitude, which can be visualized as differences in image contrast. One of the major advantages of phase contrast microscopy is that living cells can be examined in their natural state without previously being killed, fixed, and stained. As a result, the dynamics of ongoing biological processes can be observed and recorded in high contrast with sharp clarity of minute specimen detail. The phase-plate increases the phase difference to half a wavelength. Destructive interference between the two sorts of light when the image is projected results in the specimen appearing as a dark object. The phase contrast microscope uses the fact that the light passing through a transparent part of the specimen travels slower and, due to this is shifted compared to the uninfluenced light. This difference in phase is not visible to the human eye. However, the change in phase can be increased to half a wavelength by a transparent...
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...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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...COURSE STRUCTURE CLASS X First Term Units I. II. III. IV Chemical Substances World of living Effects of Current Natural Resources Total Marks : 90 Marks 33 21 29 07 90 Theme : Materials Unit : Chemical Substances - Nature and Behaviour (30 Periods) Chemical reactions : Chemical Equation, Balanced chemical equation, implications of a balanced chemical equation, types of chemical reactions : combination, decomposition, displacement, double displacement, precipitation, neutralization, oxidation and reduction. Acids, bases and salts : Their definitions in terms of furnishing of H+ and OH- ions, General properties, examples and uses, concept of pH scale(Definition relating to logarithm not required), importance of pH in everyday life; preparation and uses of sodium hydroxide, Bleaching powder, Baking soda, washing soda and Plaster of Paris. Metals and non metals : Properties of metals and non-metals, reactivity series, formation and properties of ionic compounds, basic metallurgical processes, corrosion and its prevention Theme : The world of The Living Unit : World of Living (20 Periods) Life Processes : "living being". Basic concept of nutrition, respiration, transport and excretion in plants and animals. Control and Co-ordination in Animals and Plants : Tropic movements in plants; Introduction to plant hormones; control and co-ordination in animals : nervous system; voluntary, involuntary and reflex action, chemical co-ordination: animal hormones. Theme : How...
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...Chapter 7 Review By refracting or bending light rays Virtual: image that can't be seen directly; real: image can be seen directly with naked eye Light passes through two lenses forming virtual image, and a magnifying glass appears larger due to refraction, the eyepiece lens contributes to magnification Illumination of a specimen from above used to examine opaque specimens, a transmitted illumination passes light up through a transparent specimen so it wouldn't be able to pass light through an opaque specimen Take the power of the objective and multiply by the power of the eyepiece A measure of its ability to gather light and resolve fine specimen detail at a fixed object distance, the difference is their N.A. For a good general overall view of the specimen Two compound microscopes connected by a bridge that allows you to see two objects in a side by side view Forensic scientist could now compare a know bullet station to an unknown, at the same time and from there could match them up Uses two separate optical paths instead of just one, and produces a 3D image of the specimen Stereoscopic microscope; wide field view, great depths of focus, large working distance, makes it ideal for viewing bulky items The refracted light beams are polarized, both polarized lights pass through the set perpendicular to the first crystal To measure spectra of microscopic samples or microscopic areas on samples The infrared micro spectrophotometer identifies the specimen, and is usually...
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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 thing but it’s much simpler and smaller, with no nucleus and a simpler membrane. Animal cells are the ones that consist of a nucleus and plant cells are the ones that consist of a organelles. 4. Animal cells don’t need cell walls. The function of cell walls is to formulate structure and animal cells don’t require that because they need space to move around. 5. From the seven properties of life I was able to identify...
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...refractor telescope uses lenses to magnify the image. The light first goes in the primary lens and then the light goes...
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...Optics Mirrors and Lenses Reflection We describe the path of light as straight-line rays Reflection off a flat surface follows a simple rule: angle in (incidence) equals angle out (reflection) angles measured from surface “normal” (perpendicular) Reflection Vocabulary Real Image – Image is made from “real” light rays that converge at a real focal point so the image is REAL Can be projected onto a screen because light actually passes through the point where the image appears Always inverted Reflection Vocabulary Virtual Image– “Not Real” because it cannot be projected Image only seems to be there! Virtual Images in Plane Mirrors Hall Mirror Useful to think in terms of images LEFT- RIGHT REVERSAL Curved mirrors What if the mirror isn’t flat? light still follows the same rules, with local surface normal Parabolic mirrors have exact focus used in telescopes, backyard satellite dishes, etc. also forms virtual image Concave Mirrors Curves inward May be real or virtual image For a real object between f and the mirror, a virtual image is formed behind the mirror. The image is upright and larger than the object. Convex Mirrors Curves outward Reduces images Virtual images Use: Rear view mirrors, store security… Refraction Light also goes through some things glass, water, eyeball, air The presence of material slows light’s progress interactions with electrical properties of atoms The “light slowing factor” is called the index...
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...For other uses, see Lens. A lens. Lenses can be used to focus light. A lens is an optical device which transmits and refracts light, converging or diverging the beam.[citation needed] A simple lens consists of a single optical element. A compound lens is an array of simple lenses (elements) with a common axis; the use of multiple elements allows more optical aberrations to be corrected than is possible with a single element. Lenses are typically made of glass or transparent plastic. Elements which refract electromagnetic radiation outside the visual spectrum are also called lenses: for instance, a microwave lens can be made from paraffin wax. The variant spelling lense is sometimes seen. While it is listed as an alternative spelling in some dictionaries, most mainstream dictionaries do not list it as acceptable.[1][2] Contents * 1 History * 2 Construction of simple lenses * 2.1 Types of simple lenses * 2.2 Lensmaker's equation * 2.2.1 Sign convention of lens radii R1 and R2 * 2.2.2 Thin lens equation * 3 Imaging properties * 4 Aberrations * 4.1 Spherical aberration * 4.2 Coma * 4.3 Chromatic aberration * 4.4 Other types of aberration * 4.5 Aperture diffraction * 5 Compound lenses * 6 Other types * 7 Uses * 8 See also * 9 References * 10 Bibliography * 11 External links * 11.1 Simulations History | This section requires expansion with: history...
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...The use of 1 Microscopes Name: Khulud Abdulaziz Nazer ID: U00045236 September 23 2014 General biology lab Section: 13 T Instructor: Tasneem Obaid Introduction: Microscopes are instruments used to enlarge objects that are too small to be seen by one’s eyes. Microscopy is the science of the examination of small objects using microscopes. Technically we have two types of microscopes, the optical microscope which was first invented in late 1500s. It uses light and glass lenses (objectives) to magnify the image of an object up to 4X, 10X, 40X and a 100X. The second type is the electron microscope which was developed at early 1900s, it uses an electron beam in the place of light and electromagnets in the place of objectives to allow a much higher resolution up to two million times. In this experiment we will be using the optical microscope and not the electron microscope to examine specimens, as it is available in almost all the laboratories. In addition, the costs of the optical microscope is too low compared to that of the electron microscope. Moreover, the optical microscope can be stored in normal room temperature and pressure not requiring a vacuum as the electron one does. Materials: Compound light microscope and stereomicroscope. Prepared dry mount of the letter “e” . A plug. Method: First of all, we used a compound light microscope to assess the letter “e”. We followed the following procedure; A slide of dry mount of letter “e” was...
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...BIO 111, Microscope Lab Write-up Directions You must type your answers neatly so I can read them. Do not tear out the pages of your lab manual and turn them in to me. Your lab write-up is due at the beginning of your next lab and should include: 1. Your name and lab section Taylor Abel 2. Results and Observations section a. Sketches of the letter e’s. Explain why they look different. The e’s all look different due to the different objectives. Each objective has a different use, 4 is for if we are trying to simply see the object up close. Any higher than that is used to be able to see organisms that you can’t see with the bare eye. b. Sketches of the water microorganisms you observed and identifications Unknown Unknown Blood Cells 3. Laboratory Review c. Type your answers to all the questions on page 24 1. a. eye lense d. Objectives e. ? f. Stage g. Course adjustment knob h. Fine focus knob i. Stage focus knob j. Field lense k. Microscope base l. Condenser m. Neck 2. a. 10 b. 40 c. 100 3. 100 4. The distance between the stage and objective. 5. Less. 6. a. Wavelength of light b. Angular aperture c. Refractive index n. Reproduce and complete Table 2 on page 25. Microscope Part | Fuction(s) | Ocular | Magnification | Objective | Magnification | Condenser | Concentrates/ Directs light beam through...
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...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 start and also a detailed description on how to operate it, in case some of the audience is unfamiliar with a microscope. I will try to give a detail description on how to do each step on operating the microscope. After the description on how to operate the microscope, I will try to provide some information on...
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... 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 looks like it is made up of tiny scales. While observing the paper with the letter e written on it, I noticed that, just like the hair, the paper does not look smooth. The paper actually looks like a bunch of threads woven together like a birds nest. The ink on the paper only seemed to stick to the top layer or two of...
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...As you embark on the question why did the people of Israel desire a king? You almost find yourself pondering when in 1 Samuel Chapter 7 you see the people thriving under the administration of Samuel’s leadership and it is a flip the scene in 1 Samuel Chapter 8. The people began crying out that they wanted a King because they no longer liked the way there issues were being resolved under the judges system. It leaves you with a thought that perhaps the people wanted a King because Samuel sons did not share his character but operated under bribery and injustice and I they looked the lens of other Nations and a King would be the answer. They people wanted a new government and new system but God desire was for them to experience great freedom both in government and as a Nation. They did not understand where God remind us in Jeremiah 23:11 that he knows the plans for our lives and when we begin creating the plans we will not get a God result. God reminds the people that this is not his plan for them and if they so desire a King he will grant the request. The issue is that God is an all-knowing God and He knows placing a King over the people will cause them to lose their liberty. In 1 Samuel 8 verse 11, God speaks to the rule and reign that a King will bring and yet the people still wanted a King. The issue that I found is that what looks good on the other side of the fence is not always greener. They were looking at other Nations and felt man’s governing rule was a greater...
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...sunken stomates and swollen stem to adapt to their arid environment. Materials: • Leaves, stems, flowers and fruits of Casuarina, Eucalyptus, Cactus, Acacia, Hakea, Spinefex, and Banksia • Internet and BIF textbook images/drawings or prepared glass slides of xerophytes • Stereo microscope • Compound Optical Microscope • Glass slides • cover slips • mounting needle • forceps • magnifying glasses or hand lens Risk Assessments: - Extra care is needed when handling microscopes and the prepared glass slides as - breakages might occur. Place the microscope and glass slides away from the edges of the table to avoid them from falling. When handling the different types of xerophytic plants, make sure they are away from eyes, nose and face as allergies or skin irritation to plants may occur if inhaled or held for too long, always wear apron or gloves if necessary. Method: 1. Observe and draw the leaves of the xerophytic plants 2. Noticing their distinctive features including the leaves, stem flowers and fruits. 3. Use a compound microscope, magnifying lens or stereo microscope to observe the positions of the stomates, presence of hair and mid vein on the leaves and other distinctive features of the specimens. 4. Use the internet for secondary sources and BIF for prepared images and compare results 5. Record observations of the specimens in a table...
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...the validity of the Thin Lens Equation. 2. Theory Lenses and mirrors are used to change the direction, orientation, and magnification of an object. This experiment used lenses known as thin spherical lenses. These lenses are called thin spherical lenses because they have spheres on each surface with large radii compared to the small thickness of the lenses. The focal length (f) of the lens is determined by using the Thin Lens Equation and substituting the objects distance (o) and image distance (i) into it. 1/i+1/o=1/f Thin Lens Equation (1) The Thin Lens Equation can be used to determine how far the object is from the lens. The next thing to find...
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