Academic journal article Forensic Science Communications

Chapter 6: Microscopy Review

Academic journal article Forensic Science Communications

Chapter 6: Microscopy Review

Article excerpt

General Discussion

This module is intended as a guide to familiarize the trainee with the operating theory and care of microscopes used in the laboratory. Emphasis is placed on proper illumination, calibration and preliminary observations made with stereomicroscopes and polarized light microscopes (PLM), which are the instruments typically used first in any fibrous evidence examinations.

Objectives

Upon satisfactory completion of this training module, the trainee will have developed and demonstrated theoretical knowledge and/or practical skills to:

1. understand microscope optics;

2. properly operate and maintain each microscope and its accessories including adjustments, cleaning and diagnosing problems;

3. establish proper microscope illumination including adjustment for Kohler illumination;

4. calibrate the ocular micrometer, and acquire proper measurements utilizing ocular and stage micrometers; and

5. select appropriate microscopes and accessories for the observational task required.

Training Steps and Check Lists

1. Reading Assignments: Complete Chapter 6 reading assignments listed in Appendix I.

2. Basic Skills

3. Practical Exercises: Complete these exercises located in Appendix II.

6-1 Familiarization with the Stereomicroscope

6-2 Familiarization with the Compound Light Microscope

Part 1 Kohler Illumination

Part 2 Basic Micrometry and Calibrating an Ocular Micrometer

6-3 Familiarization with the Polarized Light Microscope

Part 1 Refractive Index by Becke Line Observations

Part 2 Observation of Extinction Positions and Interference Colors in Crossed Polars

Competency Evaluation

The trainee shall be evaluated by quizzes on theoretical knowledge and basic practical skills as specified in the module objectives. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.