RH

Microscopes & Wet Mount Slides Lab - Vocabulary Flashcards

Activity 1: Compound Light Microscope

  • Parts labeled on the diagram (identify each part):

    • 1: ocular lens / eye piece — 10x magnification
    • 2: rotating nose piece
    • 3: objective lenses
    • 4: stage
    • 5: diaphragm
    • 6: light source
    • 7: arm
    • 8: coarse adjustment
    • 9: fine adjustment
    • 10: base

  • Functions of microscope parts (summary of lab table):

    • Ocular lens:
    • The observer looks through, and it magnifies the specimen by 10x.
    • Objective lenses:
    • Four lenses: scanning (4x), low power (10x), high power (40x), oil immersion (100x).
    • Stage:
    • Where the slide is placed and held.
    • Condenser:
    • Focuses and concentrates the light on the specimen.
    • Diaphragm:
    • Adjusts the amount of light reaching the specimen.
    • Coarse Adjustment:
    • Moves the stage up and down to focus the specimen (rough focus).
    • Fine Adjustment:
    • Provides precise focusing once the initial coarse focusing has been completed.

  • Magnification calculation (total magnification per lens)

    • Concept: Total magnification is the product of the ocular magnification and the objective magnification.
    • Formula: M{\text{total}} = M{\text{ocular}} \times M_{\text{objective}}
    • Magnification details:
    • Ocular Lens: Magnification = 10x; Total Magnification = Not Applicable
    • Scanning Lens: Magnification = 4x; Total Magnification = 10!\times!4 = 40 => 40x
    • Low Power Lens: Magnification = 10x; Total Magnification = 10!\times!10 = 100 => 100x
    • High Power Lens: Magnification = 40x; Total Magnification = 10!\times!40 = 400 => 400x
    • Oil Immersion Lens: Magnification = 100x; Total Magnification = 10!\times!100 = 1000 => 1000x

Activity 2: Letter “e” slides

  • Procedure: Obtain a letter “e” slide and view it under scanning, low power, and high power lenses.

    • a. Magnification observations:
    • Total magnification while using the low power lens: 100x
    • Total magnification while using the high power lens: 400x
    • b. Orientation of the letter “e”: it appears as upside down.
    • c. Effect on field of view with higher magnification: the field of view became smaller.

  • Quick reference for microscope parts (from slide):

    • Ocular lens — The observer looks through; magnifies by 10x.
    • Objective lenses — four lenses: scanning (4x), low power (10x), high power (40x), oil immersion (100x).
    • Stage — Where the slide is placed and held.
    • Condenser — Focuses and concentrates light on the specimen.
    • Diaphragm — Adjusts the amount of light reaching the specimen.
    • Coarse Adjustment — Moves the stage up/down for rough focus.
    • Fine Adjustment — Provides precise focusing after coarse focus.

Activity 3: Colored Thread Slide

  • Question 5: Obtain a colored thread slide (red, blue, and yellow threads) and perform the activity.
    • a. At higher magnification, if a slide is thick, will only parts of the specimen come into focus at one time or will all parts come into focus at the same time?
    • Answer (as given): It will come into focus at one time.

Activity 4: Wet Mount Slide

  • Question 6: Read the lab instructions and create a wet mount with dog (or horse) hair.
    • a. How to place the coverslip on the microscope slide:
    • At a 45-degree angle, then let it drop into place.
    • b. Should you press on the coverslip if air bubbles are trapped between the slide and the coverslip?
    • No.

True/False a.k.a. Statements (Section 7)

  • Statements to evaluate as True (T) or False (F):

    • F: On high power, you should use the coarse adjustment knob.
    • T: The diaphragm determines how much light shines on the specimen.
    • T: The low power objective lens has a greater magnification than the scanning objective lens.
    • F: The fine focus knob visibly moves the stage up and down.
    • T: Images viewed in the microscope will appear upside down.
    • F: The type of microscope you are using is a scanning microscope.
    • F: For viewing, microscope slides should be placed on the objective.
    • T: In order to switch from low to high power, you must rotate the rotating nosepiece.
    • F: The total magnification of a microscope is determined by adding the ocular lens power to the objective lens power.

  • 8. When first viewing a specimen, you should always start with the scanning 4x objective lens.

  • 9. You should carry the microscope by the arm and the base_.

Page 4: Care and Handling Questions

    1. When viewing specimens through the high power objective lens (40x) and the oil immersion objective lens (100x), why should the coarse adjustment not be used?
    • Answer: Break the slide or lens.
    1. Describe at least two important steps that should be taken to care for the microscope during and after use in the laboratory.
    • Examples from transcript:
    • Clean the eyepiece before using.
    • Grab the arm and hold the base when moving.

  • Practical reminders (from statements and steps):

    • Start with the scanning 4x objective to locate the specimen before moving to higher magnifications.
    • Carry the microscope by the arm and base to prevent damage.
    • Do not press on the coverslip if air bubbles are present; place the coverslip gently.
    • Coarse adjustment should not be used at high magnification (e.g., 40x or 100x) to avoid breaking slides or lenses.
    • The diaphragm controls light intensity; adjust as needed for contrast.
    • Total magnification is the product of ocular and objective magnifications, not the sum.

  • Summary of key concepts and practical references:

    • Magnification principles:
    • Ocular lens magnification: 10x.
    • Objective lenses and their magnifications: 4x (scanning), 10x (low power), 40x (high power), 100x (oil immersion).
    • Total magnification for each objective: 40x, 100x, 400x, 1000x respectively when paired with the 10x ocular.
    • Mathematical relation: M{\text{total}} = M{\text{ocular}} \times M{\text{objective}} = 10 \times M{\text{objective}}
    • Orientation and field of view:
    • Higher magnification yields a smaller field of view.
    • Images often appear upside down when viewed through the microscope.
    • Wet mount technique:
    • Place coverslip at a 45-degree angle to prevent air bubbles and gradually lower it.
    • Care and handling:
    • Clean eyepiece before use.
    • Carry by the arm and base; move slowly to prevent accidents or damage.

  • Definitions and quick references:

    • Ocular lens: the eyepiece through which you view the specimen.
    • Objective lenses: four primary lenses with distinct magnifications.
    • Stage: platform where slides are placed.
    • Condenser: concentrates light onto the specimen.
    • Diaphragm: regulates light intensity.
    • Coarse focus: rough focusing; moves the stage significantly.
    • Fine focus: precise focusing; small adjustments.
    • Wet mount: prepared slide with a specimen suspended in liquid between slide and coverslip.
    • Field of view: the visible area through the microscope; decreases as magnification increases.

  • Notes on numerical references and formulas:

    • Lens magnifications: Scanning 4x, Low Power 10x, High Power 40x, Oil Immersion 100x
    • Ocular magnification: 10x
    • Total magnifications: 40x, 100x, 400x, 1000x corresponding to the four objective lenses when using the 10x ocular
    • Formula for total magnification: M{\text{total}} = M{\text{ocular}} \times M_{\text{objective}} where $M$ denotes magnification and units are "x" (e.g., 40x)