LabLearner—The Science of Learning
LabLearner—The Science of Learning

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Microscopic Explorations

Investigation 2 – Lab

 

 

 

 

 

 

 

Back to Investigation 2

ASK WHY

Microscopes are one of the most important scientific instruments developed. In fact, in the medical field, microscopes are largely responsible for making modern medicine “modern”!

BRANCH OUT

While we often think of microscopes in terms of research with cells, however, microscopes are used in many other fields where significant magnification is required. Professions that rely on microscopes include jewelers, gemologists (study gems), geologists (study rocks), and forensic scientists (study crimes).

BE PREPARED

Group materials:
  • 1 crossed fibers slide
  • 1 cork slide
  • 1 ink pad
  • 1 pair of scissors
  • 1 piece of white paper (8 ½ “ x 11”)
  • 1 100 ml beaker of water
  • 1 paper towel
  • 1 roll of clear tape
Pair materials:
  • 1 microscope
  • 2 glass slides
  • 2 glass cover slips
Individual materials: 
  • 1 Student Data Record

Teacher Preparation

    1. Place materials required by student groups at the distribution point.

    2. Divide the class into pairs. Assign two to three student pairs to a table to form a larger group of students. Each student pair will receive one microscope, 2 glass slides and 2 glass cover slips, but will need to share the other materials at the table with the other student pairs.

    3. Direct each of the five student groups to obtain the following necessary materials from the distribution point: one (1) crossed fibers slide, one (1) cork slide, one (1) ink pad, one (1) pair scissors, one (1) piece of white paper (8 ½ “ x 11”), one (1) 100 ml beaker of water, one (1) paper towel, and one (1) roll of clear tape.

    GET FOCUSED

    There are two Trials in this Lab. Both give students the opportunity to use the compound microscope with each of its three objective lenses. In Trial One, students will examine two different prepared slides. In doing so, they will discover the answer to the following question:

    • What is the relationship between the resolution of an image, the field of view of an image, and the magnification of the lens used to view an object?

    In Trial 2, students will take their fingerprint and observe the print with the unassisted eye and the compound microscope. Students will soon use these skills again in Investigations 3 and 4. By the end of the Lab, students will be able to answer the question:

    • How can a specimen be prepared for microscopic analysis?

    Trial 1:

    Trial One has been designed to provide students with an opportunity to review the operation of the compound microscope as they observe the structures of two specimens: cork and pieces of thread. As students conduct this trial, they will view both specimens with the low power (4X) objective as well as with the medium (10X) and high power (40X) objectives. Students previously used the 4X objective in Investigation One but did not view specimens with the 10X or 40X objectives. By sketching and describing their observations of each specimen under all three objectives, students will compare the differences in the magnification, resolution, and field of view of each objective. In addition to their descriptions, students will calculate the power of magnification observed with each objective.

    KEYS: TRIAL 1

    Trial 2:

    In Trial 2 students will take their fingerprint and observe the print with the unassisted eye and the compound microscope. In doing so, students will learn one way in which to prepare a specimen for microscopic analysis, a procedure they will use again in Investigations Three and Four as they prepare specimens of plant and animal tissues. In addition to the procedural knowledge of slide preparation students will gain in Trial Two, they will again have the opportunity to observe differences in the magnification, resolution, and field of view afforded by the three objectives of the microscope.

    KEYS: TRIAL 2

    CLEAN UP

    Let students know your expectations for clean-up. Ask them to clean up.