Lab safety in histopath Flashcards
art of analyzing and interpreting the shapes, sizes and architectural patterns of
cells and tissues within a given specific clinical background
Histopathology
Provide the basic concepts about the principles and technicalities
involved in histopathologic procedures
Histopathologic technique
comprised of a number
of glass beakers for filling
different processing
chemicals
Automatic tissue processor
instrument with the help of which
sections of tissues are cut and the process of cutting
thin sections
Microtome
refrigerated apparatus
used in fresh tissue microtomy, for
freezing the tissue into the block
holder to correct degree of hardness
to facilitate easier and faster
sectioning.
Cryostat
Temperature of cryostat
-5⁰C
to-30⁰C (ave is -20°C)
a timing disc which
rotates after specific
intervals, and a specimen
container holding assembly.
Automatic tissue processor
used to float paraffin ribbons, to stretch sections and
remove wrinkle. The water temperature should be about 10 degrees below
the melting point of paraffin
TISSUE WATER BATH
It is one of the important
machines required in
histopathology for
processing organ and
tissues before being
embedded in paraffin wax
Automatic tissue processor
Removing moisture from samples
Laboratory oven
What is the temperature of tissue water bath
45 - 50C
2 functions laboratory oven
- drying
- dehydrating
optimizes
times during stain process to
maximize efficiency in obtention of
results for a timely diagnosis
Automated tissue stainer
equipment
that is used by both the pathologist and
the histotechnologist.
Microscope
examines the slide under
the microscope to identify a disease
process or an abnormality that will
directly affect the patient’s treatment
Pathologist
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.
Histotechnologist
3 objectives of the microscope
(1) it must magnify the object
(2) it must resolve the details
of the object
(3) it must make these details
visible.
microscope with more than
one lens and its own light
source.
COMPOUND MICROSCOPE
3 types of compound microscope viewing heads
Monocular Heads
light
weight and are inexpensive.
- Monocular Heads
- Binocular heads
- Trinocular Heads
- It is the most common choice
Binocular heads
more expensive compound microscope
Trinocular Heads
The main framework of the Compound
Microscope:
Base
Arm
Stage
Substage
Mechanical Stage
permits movement of
the stage while holding the slide in the
phase of focus
Mechanical Stage
located directly under the
stage and holds the condenser and
diaphragm.
Substage
the flat platform where the
slide is placed for examination.
Stage
supports and holds the magnifying
and adjustment system. It can be used as
a handle for carrying the microscope.
Arm
-provides support for the microscope. The base should be large and
solid enough to allow the microscope to
stand by itself.
Base
parts of the lens system
Nosepiece
Objectives
Focal length
located at the end of the body
tube for holding the objectives
Nosepiece
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.
Objectives
purpose of the objective is to
increase or decrease magnification.
Objectives
When one objective is focused
on the turret, all lenses will be approximately
in focus
Par focal
the distance between outer lens
of objective and the cover glass of the slide
under examination.
Focal length
the process that
increases the size of the structure
under examination.
Magnification
the product of the
magnifying power of the
objective and eyepiece, with a
normal tube length of 160 mm
Total magnification
process of ensuring and maintaining personal as
well as environmental health and safety in the
laboratory
Risk management
must be
detailed to include control of hazardous substances, risk assessments, and other health
and safety information relevant to handling of specimens
Standard operating procedures
The first step is to identify hazards that can potentially cause harm in the laboratory.
sop
exposures to chemical hazards
Chemical Hazards
Where can you obtain exposures to chemical hazards
can occur both during use and
with poor storage
terms used to define the maximum allowable airborne concentration
of a chemical (vapor, fume or dust) to which a worker may be exposed
Permissible Exposure Limits (PELs), Threshold Limit Values (TLVs), or
Occupational Exposure Limits (OELs)
a regulatory limit on the amount or concentration of a substance in
the air.
PELs – Permissible Exposure limits
represents the maximum level of an airborne substance that a worker
can be safely subjected to without being susceptible to harm or injury.
TLVs – Threshold limit values
indicates the level of admissible exposure, for a length of time
(usually 8 hours), to a chemical or physical hazard that is not likely to
affect the health of a worker.
OELs – Occupational Exposure Limits
Chemical label content
Chemical name and, if a mixture, names of all ingredients;
Date purchased or made;
* Expiration date, if known;
* Hazard warnings and safety procedures.
Chemical Hazards
Irritants
Corrosive
Toxic materials
Carcinogens
Sensitizers
Chemicals that cause reversible
inflammatory effects at the site of
contact with living tissue,
especially the skin, eyes and
respiratory passages
Irritants
Cause destruction or
irreversible alterations
when exposed to living
tissue.
Corrosive chemicals
Capable of causing death by ingestion,
skin contact, or inhalation at certain
specified concentrations
Toxic materials
Substances that induce tumors in
animals and humans
Carcinogens
Example of toxic materials
methanol, chromic acid, osmium
tetroxide and uranyl nitrate
Example of carcinogen
chloroform, chromic acid,
formaldeyhyde, auramine, basic
fuchsin
Cause allergic reactions in a substantial
proportion
Sensitizers
slips and falls from working in wet locations and the ergonomic hazards of
lifting, pushing, pulling, and repetitive tasks.
Physical Hazards
Other physical hazards often unnoticed are
electrical, mechanical, acoustic, or
thermal in nature
Substances that ignite a certain
temperature
Combustibles
What is flash point
In the USA, OSHA defines “flash point” as
100°F (38°C) while the Department of
Transportation defines it as 141°F (or
60.5°C).
initiate or promote combustion and
present a serious fire risk when in
contact with certain substances
Oxidizers
Example of oxidize
◦ sodium iodate, mercuric oxide
◦ chromic acid
refer to anything that can cause
disease in humans, regardless of their
source.
Biological Hazards
one of the most
important health hazards,
Allergens
Hazards and Handling of Common Histological
Chemicals
Hydrogen peroxide
Methanol
Nitric acid
Xylene
Cryogens
Osmium tetroxide
Sodium hypochlorite
Sulfuric acid
degree to which healthcare services strive
to provide accurate desired outcomes for
patients and are consistent with current
professional knowledge
Quality
system of routine technical
activities
Quality control
planned system of review procedures conducted by personnel not directly
involved in the laboratory process
Quality Assurance
Getting the right test at the right time on the right specimen from the right
patient with right diagnosis and the right price.
data of QC provides the data for QA
Quality assessment programs
- College of American Pathologists (CAP)
- United Kingdom National External Quality Assessment Service
stained preparations from departmental archival records are used to
assess the quality of staining
selective system
QA’s two distinct systems:
selective system
distributive system
participating laboratories are asked to stain sections that have been
submitted by the scheme organizer
distributive system
means that the report generated by
the lab are accurate.
QMS
Effective QMS
- Skilled
histotechnologist/nicians - Proper specimen collection
- Proper processing of
specimen - Efficient processing of
results - High quality of reagents
and equipment - Preventive Maintenance of
equipment - Continuous professional
education of staff - Documentation and
control - Proper coordination
- Timely customer’s
feedback
Example of Pre-analytical phase
- Collection of the right specimen
- The proper fixation of the specimen
- The correct identification of the spec
- The timely transportation of the specimen
Example of Analytical phase
- Grossing
- Processing
- Procedure reliability using technical manual
- Reagent integrity and efficiency
- Cutting of paraffin sections
- Staining
- Slide labeling
Example of Post-analytical phase
- Diagnosis (hard copy) free of clerical errors.
- Reports reaches the appropriate
*
clinicians/surgeons.
Filing of paraffin blocks - Slides storage
Average temperature of cryostat
15-20C
