LECTURE 1.1: Risk Management and Safety in the histopathology Laboratory & Introduction to Tissue Processing

RISK MANAGEMENT

This pertains to personal as well as environmental health and safety.

RISK MANAGEMENT

This pertains to the process of ensuring and maintaining personal as well as environmental health and safety in the laboratory.

To identify all hazards in and emanating from the laboratory.

This is the first step in risk management.

Cutting of one's finger or hand on microtome knives.

One of the most common accidents in the laboratory involves?

Read the manual that accompanies the equipment.

1st and most important step in the operation of any piece of equipment.

Instrumentation in Histotechnology

Care, appropriate use and maintenance of equipment

The Care and Use of the Microscope

Presentations are communication tools that can be used as lectures.

Quality Control

The quality of sections and quality of staining produced by the histopathology laboratory must be checked before issuing them to the pathologist.

False, not enough

Preparing an inventory of chemical reagents is enough to identify hazards in histotechnology.
True or False?

Electrical ; mechanical ; biological

_____, ____and ____hazards must also be included.

Standard operating procedures

______ must be detailed to include control of hazardous specimens, risk assessments, and other health and safety information relevant to handling specimens.

Equipment malfunction

___ due to poor maintenance and poor-quality reagents can result in poor processing of tissues or inaccurate staining results.

1. Microscope

2. Microtome

3. Cryostat

4. Autotechnicon

5. Automated coverslipper

6. Automated H and E Stainer

The major pieces of equipment for any surgical pathology laboratory are:

FILE INFORMATION

It is imperative that the laboratory maintain a current file for every piece of equipment in the laboratory.

• Name

• Manufacturer

• Model Number

• Serial Number

The file information should include:

FILE INFORMATION

Record of preventive maintenance performed, as prescribed by the manufacturer. Record of service calls and repairs performed

FILE INFORMATION

Copy of operating manual

PATHOLOGIST

He/she examines the slide under the microscope to identify a disease process or an abnormality that will directly affect the patient's treatment.

HISTOTECHNOLOGIST

He/she examines the same slide microscopically for quality control to determine whether all technical processes are done properly and if a slide of diagnostic quality has been achieved.

MICROSCOPE

Is one piece of equipment that is used by both the pathologist and the histotechnologist.

1. Base

2. Arm

3. Stage

4. Substage

5. Mechanical Stage

The main framework of the Compound Microscope consists of:

BASE

Provides support for the microscope.

BASE

It should be large and solid enough to allow the microscope to stand by itself.

ARM

Supports and holds the magnifying and adjustment system.

magnifying ; adjustment

The arm supports and holds the ___ and ___system.

ARM

It can be used as a handle for carrying the microscope.

STAGE

Is the flat platform where the slide is placed for examination

SUBSTAGE

Is located directly under the stage and holds the condenser and diaphragm.

condenser ; diaphragm

The substage is located directly under the stage and holds the ___and ___.

MECHANICAL STAGE

Permits movement of the stage while holding the slide in the phase of focus.

1. it must magnify the object,

2. it must resolve the details of the object

3. it must make these details visible

To be useful, a microscope must accomplish three things:

OPTICAL COMPOUND MICROSCOPE

The most common (and the first to be invented) microsope, which uses light to image the sample.

• Electron microscope

  • Transmission electron microscope

  • Scanning electron microscope

• Ultra-microscope

• various types of Scanning probe microscope

Other major types of microscopes:

• Transmission electron microscope

• Scanning electron microscope

The two types of electron miscroscope:

1. Nosepiece

2. Objectives

3. Body tube

4. Eyepiece

5. Focal Length

The parts of the lens system are:

NOSEPIECE

Is located at the end of the body tube for holding the objectives.

OBJECTIVES

Consist of a system of lenses located at the end of the body tube that is held in place by the nosepiece and is closer to the slide under examination.

Increase or decrease magnification.

The purpose of the objective is to?

OBJECTIVES

Are mounted on a revolving turret allowing for the change of objectives.

Parfocal

When one objective is focused on the turret, all lenses will be approximately in focus. If this is true, the microscope is said to be ____.

FOCAL LENGTH

Is the distance between outer lens of objective and the cover glass of the slide under examination.

EYEPIECE

It is also referred to as the ocular.

ocular

The eyepiece is also referred to as the?

EYEPIECE

This is the lens system nearest the eye.

EYEPIECE

This receives the image from the lens of the objective, further magnifying the object being examined by approximately 10x.

MAGNIFICATION

Is the process that increases the size of the structure under examination

MAGNIFICATION

It is achieved by the use of the microscope's lens system.

TOTAL MAGNIFICATION

The ________ of a microscope is the product of the magnifying power of the objective and eyepiece, with a normal tube length of 160 mm.

160 mm

The total magnification of a microscope is the product of the magnifying power of the objective and eyepiece, with a normal tube length of ___.

Objective x Eyepiece

TOTAL MAGNIFICATION FORMULA:

Objective x Eyepiece x (Working Tube Length/Normal Tube Length)

TOTAL MAGNIFICATION FORMULA (if the microscope is fitted with a draw tube):

1. Compound Microscope

2. Fluorescence Microscope

3. Electron Microscope

DIFFERENT TYPES OF MICROSCOPES:

COMPOUND MICROSCOPE / COMPOUND LIGHT MICROSCOPE

Is a microscope with more than one lens and its own light source.

COMPOUND MICROSCOPE

In this type of microscope, there are ocular lenses in the binocular eyepieces and objective lenses in a rotating nosepiece closer to the specimen.

bright field microscope

Because it contains its own light source at its base, a compound light microscope is also considered a ______, which means that the specimen is lit from below and viewed from above.

BRIGHT-FIELD MICROSCOPY

Is the simplest and most popular of all techniques used for illumination of samples in light microscopes

dark sample on a bright background

The typical appearance of a bright-field microscopy image is a ______, hence the name.

absorption

With bright field illumination, the sample’s contrast comes from its ___of the light, as opposed to dark field illumination where the contrast comes from the sample scattering the light.

scattering

With bright field illumination, the sample’s contrast comes from its absorption of the light, as opposed to dark field illumination where the contrast comes from the sample ____ the light.

1. lens system condenser

2. objective

3. ocular

The compound microscope consists of the:

CONDENSER

This brings the parallel rays of light to a point of focus in the plane of the object.

OBJECTIVE

This magnifies the object being viewed and focuses a real image in the upper part of the body tube.

OCULAR

This further magnifies the image formed by the objective.

surgical pathology

The compound microscope currently in use for _______ consists of its framework and its two separate lens system.

1. Monocular heads

2. Binocular heads

3. Trinocular heads

VIEWING HEADS:

MONOCULAR HEADS

Only use one eyepiece when viewing the specimen. You are restricted if you want to use an LCD camera because this would occupy the eyepiece.

MONOCULAR HEADS

Are light weight and are inexpensive.

BINOCULAR HEADS

Have two eyepieces and are more convenient and comfortable to use.

BINOCULAR HEADS

It is the most common choice.

TRINOCULAR HEADS

Have a third eyepiece tube that can be used by another person simultaneously or by an LCD camera.

TRINOCULAR HEADS

This is more expensive than the other two types of viewing heads.

45 degree ; 30 degree

Usually the heads can be set to a ____ or a ____ angle with sliding or hinge adjustment for inter-pupillary distance.

BRIGHT-FIELD MICROSCOPY

Is generally used in compound microscopes, where light is either passed through, or reflected off, a specimen.

Simple light microscopes

_______ are sometimes referred to as bright field microscopes where a specimen is placed on the stage of the microscope and incandescent light from the microscope’s light source is aimed at a lens beneath the specimen.

CONDENSER

Simple light microscopes are sometimes referred to as bright field microscopes where a specimen is placed on the stage of the microscope and incandescent light from the microscope’s light source is aimed at a lens beneath the specimen. This lens is called a?

CONDENSER

Usually contains an aperture diaphragm to control and focus light on the specimen; light passes through the specimen and then is collected by an objective lens situated in a turret above the stage.

aperture diaphragm

The condenser usually contains an ____ to control and focus light on the specimen; light passes through the specimen and then is collected by an objective lens situated in a turret above the stage.

DARK FIELD MICROSCOPY / DARK FIELD ILLUMINATION

Is a technique used to observe unstained and transparent samples causing them to be clearly visible and appear brightly lit against a dark, almost purely black background.

stereomicroscopes ; more conventional compound microscopes

The principal elements of dark field illumination are the same for both _____and ________.

PHASE CONTRAST MICROSCOPY

Is an optical microscopy illumination technique in which small phase shifts in the light passing through a transparent specimen are converted into amplitude or contrast changes in the image

PHASE CONTRAST MICROSCOPY

It is a type of light microscopy that enhances contrasts of transparent and colorless objects by influencing the optical path of light.

PHASE CONTRAST MICROSCOPY

This is able to show components in a cell or bacteria which would be very difficult to see in an ordinary light or bright field microscope.

PHASE CONTRAST MICROSCOPY

This microscope technique makes it possible to study the cell cycle in live cells.

TRUE

The use of phase contrast does not require staining to view the slide. True or False?

POLARIZED LIGHT MICROSCOPY

Is a contrast-enhancing technique that improves the quality of the image obtained with birefringent materials when compared to other techniques such as bright field microscopy, phase contrast microscopy and dark field microscopy.

POLARIZED LIGHT MICROSCOPY

It is designed to examine specimens that are visible primarily due to their optically anisotropic character.

1. The polarizer situated below the specimen stage usually fixed in the left-to-right, East-West direction, although this is usually rotatable through 360 degrees.

2. The analyzer, usually aligned North-South but again rotatable on some microscopes, is located above the objectives and can be moved in and out of the light path as required.

2 ESSENTIAL COMPONENTS OF POLARIZED LIGHT MICROSCOPY

below the specimen stage ; left-to-right, East-West direction

In polarized light microscopy, the polarizer is situated ________ usually fixed in the __________ although this is usually rotatable through 360 degrees.

North-South ; above the objectives

In polarized light microscopy, the analyzer usually aligned ___ but again rotatable on some microscopes, is located ____ and can be moved in and out of the light path as required.

FLUORESCENCE MICROSCOPE

Refers to any microscope that uses fluorescence to generate an image.

fluorescence

When certain compounds are illuminated with high energy light, they emit light of a lower frequency. This effect is known as?

FLUORESCENCE MICROSCOPE

Is a precision instrument intended for microscopic detection of tubercle bacilli in specimens in the routine diagnostic TB laboratory.

tubercle bacilli ; TB

The fluorescence microscope is a precision instrument intended for microscopic detection of ___ in specimens in the routine diagnostic ___ laboratory.

FLUORESCENCE MICROSCOPE

Requires intense, near-mono-chromatic, illumination which some widespread light sources, like halogen lamps cannot provide.

1. xenon arc lamps or

2. mercury-vapor lamps with an excitation filter

3. lasers

4. high-power LEDs

Four main types of light source:

FLUORESCENCE MICROSCOPE

This method can be extremely sensitive, allowing the detection of single molecules.

fluorescein or rhodamine

Examples of commonly used fluorophores are?

ELECTRON MICROSCOPE

Is a microscope that uses a beam of accelerated electrons as a source of illumination.

ELECTRON MICROSCOPE

Has a higher resolving power than a light microscope and can reveal the structure of smaller objects.

ELECTRON MICROSCOPE

Functions similarly to an optical scope except that, instead of visible light, a stream of electrons is used to illuminate the specimen.