Microscopy Notes PDF

***Diocese of Baguio -- Schools*** **Saint Louis School of Pacdal, Inc.** *Siapno Road, Pacdal Circle, Baguio City 2600, Philippines* E-mail: Phone. No. (074) 661-4223 **Christian Character, Excellence, Servant Leadership, & Stewardship** **MICROSCOPY** **HISTORY OF MICRO...

***Diocese of Baguio -- Schools*** **Saint Louis School of Pacdal, Inc.** *Siapno Road, Pacdal Circle, Baguio City 2600, Philippines* E-mail: Phone. No. (074) 661-4223 **Christian Character, Excellence, Servant Leadership, & Stewardship** **MICROSCOPY** **HISTORY OF MICROSCOPY** The **microscope** is a device used to observe objects that are too small to be seen by the naked eye. The word came from the ancient Greek word *mikros*, meaning "small", and *skope* which means \"to look or see.\" The science of using microscope to view small objects is called **microscopy**. There are some disputations as to who invented the microscope. It was **Zacharias Jansen**, a Dutch reading glassmaker, who invented the first microscope around 1590 when he placed two magnifying glasses in a tube. Later in mid-1600s, **Anton Van Leeuwenhoek**, a Dutch fabric maker, made significant improvements to the compound microscope. Through the microscope, Leeuwenhoek was able to discover bacteria, protist, and blood cells. +-----------------------------------+-----------------------------------+ | **Scientists** | **Contributions** | +===================================+===================================+ | **Zacharias Jansen** | Invented the first compound | | | microscope | +-----------------------------------+-----------------------------------+ | **Robert Hooke** | Used a compound microscope to | | | observe "cells" in cork | +-----------------------------------+-----------------------------------+ | **Antoine Van Leeuwenhoek** | Improvements to the compound | | | microscope | | | | | | Father of Microbiology | +-----------------------------------+-----------------------------------+ | **Joseph Jackson Lister** | Reduces spherical aberration or | | | the \"chromatic effect\" thus | | | better magnification | | | | | | First prototype of compound | | | microscope | +-----------------------------------+-----------------------------------+ | **Richard Zsigmondy** | Developed the ultramicroscope | +-----------------------------------+-----------------------------------+ | **Frits Zernike** | Invented the phase-contrast | | | microscope | +-----------------------------------+-----------------------------------+ | **Ernst Ruska** | Co-invented (with Knoll) the | | | electron microscope | +-----------------------------------+-----------------------------------+ | **Gerd Binnig & Heinrich Rohrer** | Invented the scanning tunneling | | | microscope | +-----------------------------------+-----------------------------------+ **THE COMPOUND MICROSCOPE** +-----------------------------------+-----------------------------------+ | **Parts** | **Functions** | +===================================+===================================+ | **Arm** | It supports the body tube of the | | | microscope and connects to the | | | base of the microscope. It is | | | used to carry the microscope. | +-----------------------------------+-----------------------------------+ | **Base** | It provides support to all other | | | parts of the microscope. | +-----------------------------------+-----------------------------------+ | **Body Tube** | It is a hollow tube where light | | | passes through from the eyepiece | | | to the revolving nosepiece. | +-----------------------------------+-----------------------------------+ | **Coarse Adjustment Knob** | It I a large knob used for focus | | | on scanning the image, usually, | | | the low-power objective lens is | | | used. | +-----------------------------------+-----------------------------------+ | **Diaphragm** | [It controls the amount of light | | | that passes through the | | | ample]. It changes | | | the amount of light that enters | | | the body tube and shines through | | | the sample o-n the stage. | +-----------------------------------+-----------------------------------+ | **Condenser** | [It is used to collect and focus | | | the illuminator\'s light | | | onto] the specimen. | | | It is located under the stage | | | often in conjunction with an iris | | | diaphragm. | +-----------------------------------+-----------------------------------+ | **Eyepiece or Ocular lens** | It allows to see the object and | | | magnifies the image 10 times. | +-----------------------------------+-----------------------------------+ | **Fine Adjustment Knob** | It is a small knob that is used | | | to move the body tube for | | | focusing the high-power lens for | | | larger magnification of the | | | sample. | +-----------------------------------+-----------------------------------+ | **Objective Lenses** | These are lenses with different | | | magnifications | | - **Scanning objectives** | | | | It magnifies the image on the | | - **Low Power Objective** | slide, usually 2x or 4 times. | | | | | - **High Power Objective** | It magnifies the image on the | | | slide usually 10 times | | - **Oil Immersion Objective** | | | | It magnifies the image on the | | | slide, usually 40 times or higher | | | | | | It uses a special oil and | | | magnifies the image on the slide. | | | ( 100x) | +-----------------------------------+-----------------------------------+ | **Lamp/Mirror** | It reflects light through the | | | sample. | +-----------------------------------+-----------------------------------+ | **Revolving Nosepiece** | It holds the objectives and | | | allows the position of the | | | objectives to change so that | | | magnification can be changed. | +-----------------------------------+-----------------------------------+ | **Stage** | It is the flat surface on which | | | the slides are placed. | +-----------------------------------+-----------------------------------+ | **Stage clips** | These clips hold the slides in | | | place. | +-----------------------------------+-----------------------------------+ **TYPES OF MICROSCOPES** Even during the discovery of the microscope, different versions of it were developed. At present, there are several types of microscopes having various structures and applications. A. **LIGHT MICROSCOPE**- The light or optical microscope uses visible light and a system of lenses to magnify the images. It can magnify a specimen about 500X. There are three types of light microscope. 1. **Simple microscope** uses a single lens for magnification. It uses a single, convex lens. 2. **Compound light microscope** is the most commonly used microscope in schools and laboratories. The compound microscope uses two optical parts, the ocular lens and objective lens, to provide up to 2000X magnification. 3. **Standard compound light microscope** uses two lenses. This microscope consists of an eyepiece lens that is in line with the revolving nosepiece.  Figure 1.6 Three Types of Light Microscope: Compound, Simple, and Standard Compound from microbenotes.com B. **ELECTRON MICROSCOPE**- The electron microscope is an advanced microscope that is powered by a beam of electrons with very short wavelengths. This microscope allows viewers to observe specimens at nanometer size. There are three kinds of electron microscope. 1. **Transmission electron microscope (TEM)** can produce images of one-nanometer size. It is used to study cells. 2. **Scanning electron microscope (SEM)** is approximately 10 times less powerful than TEM. This microscope produces high-resolution, sharp, black and white three-dimensional images. 3. **Reflection electron microscopy (REM)** uses an electron beam. It detects the elastically scattered electrons.  **HOW TO FOCUS YOUR MICROSCOPE** The proper way to focus a microscope is to start with the lowest power objective lens first and while looking from the side, crank the lens down as close to the specimen as possible without touching it. Now, look through the eyepiece lens and focus upward only until the image is sharp. If you can't get it in focus, repeat the process. Once the image is sharp with the low-power lens, you should be able to simply click in the next power lens and do minor adjustments with the fine adjustment knob. If your microscope has a fine focus adjustment, turning it a bit should be all that's necessary. Continue with subsequent objective lenses and fine focus each time. Note: Both eyes should be open when viewing through the microscope. This prevents eye fatigue, which occurs when the non­viewing eye is kept closed. Keeping both eyes open does take some practice, but it is highly recommended. Also, you should never let your eye touch the ocular lens. If your eyelashes touch the lens, you are to close. Always remove eyeglasses when viewing through a microscope. If your eyeglass lens touches the microscope, it may get scratched. **BASIC RULES FOR TAKING CARE OF THE COMPOUND MICROSCOPE** 1\. Hold the microscope firmly by the arm only and supporting the base with the other hand. Never grab it by the eyepiece holder.  Figure 1.16 Proper Way of Holding a Microscope from slideplayer.com 2\. Always turn the illuminator off when not in use. 3\. Always make sure the stage and lenses are clean before putting the microscope away. 4\. Use good quality lens tissue on any optical surface. Organic solvents may separate or damage the lens elements or coatings 5\. Clean the oil immersion immediately after use. 6\. Focus smoothly. Don\'t try to speed through the focusing process force anything 7\. If it isn\'t working, do not try to fix it unless you know what you are doing. 8\. Cover the instrument with a dust jacket when not in use. 9\. Keep the microscope in a clean, dry place.