{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}



Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
K101 LAB EXERCISE 1 MICROSCOPY AND CELL STRUCTURE The world is full of magic things waiting patiently for our senses to sharpen.” --John Keats” This exercise is designed to guide you in learning the parts of a light microscope and to teach you the uses as well as the limitations of this very important biological instrument. You will have a chance to practice using both the compound light microscope and the dissecting microscope. While working through this exercise refer to Figs. 1 and 2 to identify the various parts of the microscopes you are using. A. Care of the Microscope Because microscopes are carefully made scientific instruments containing many specially tooled parts (such as lenses) they are relatively expensive. A student-grade light microscope costs about $2,000 - $5,000. A research-grade microscope in the laboratory costs from $20,000 to as much as $150,000! Thus, great care must be taken in handling your microscope. 1. To carry a microscope, place the palm of your hand beneath the base of the microscope while grasping the arm of the microscope with the other hand. Carry the microscope in an upright position so various parts do not falloff. 2. To clean microscope lenses use only lens paper or cotton swabs. Kimwipes or paper towels contain wood fibers that are abrasive and therefore undesirable for cleaning the lens surface. Use either water or 95% ethyl alcohol to clean lenses of student microscopes. Lens paper squares in covered dishes, and dropper bottles of distilled water and alcohol may be found in the drawers under your laboratory bench. 3. Do not force any adjustments on your microscope. Ask your Teaching Assistant (TA) for assistance if you cannot adjust your microscope satisfactorily. If your microscope does not work properly check first with your TA before putting the defective microscope on the front bench (where it will be tuned up if needed). B. Anatomy of The Compound Microscope : Purpose of this activity: Locate all of the parts mentioned below on your microscope and locate them on the attached diagram. The compound microscope is so-called because it has two sets of lenses, the lens in the eyepiece or ocular and the lens in the objective. Both lenses contribute to the magnification (the amount an image is enlarged) and resolution (the ability to produce a sharp image between of two points such that both points can still be distinguished from each other). 1. Obtain a compound microscope and locate the eyepiece or ocular. Our microscopes have two eyepieces and are called binocular microscopes. If you wear glasses, you may want to see what works best for you – leaving them on or removing them to look through the microscope. The magnification provided by the eyepiece (ocular) lens is etched on the piece and can range from 8X to l2.5X. Student scopes most commonly have l0X oculars. The number etched on the eyepiece indicates how many times the specimen size is increased by the ocular lens. What is the number on your ocular lens? ______________________ 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2. Now locate the set of objective lenses on your microscope. The objective lenses are
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}