1-HISTOLOGY AND ITS METHODS Flashcards
is an instrument that magnifies an image and allows visualization of greater detail than is possible with the unaided eye
Microscope
Single lens
Magnifying Glass
Simple Microscope
Systems (multiple) of lens
Used in Laboratories
Compound Microscope
is the ability of a microscope lens or optical system to produce separate images of closely positioned objects
smallest detail a microscope can resolve
Resolving Power
ability of the microscope to distinguish details. To
detect 2 objects as different objects.
Resolution
ability of microscope to see small objects seem larger
Magnification
(EYE VS INSTRUMENT RESOLUTION)
Human eye
0.2 mm
(EYE VS INSTRUMENT RESOLUTION)
Bright-field microscope
0.2 μm
(EYE VS INSTRUMENT RESOLUTION)
Scanning Electron Microscope (SEM)
2.5 nm
(EYE VS INSTRUMENT RESOLUTION)
Transmission Electron Microscope (TEM) - Theoretical
0.05 nm
(EYE VS INSTRUMENT RESOLUTION)
Transmission Electron Microscope (TEM) - Tissue Section
1.0 nm
(EYE VS INSTRUMENT RESOLUTION)
Atomic Force Microscopy
50.0 pm
Distance Between Resolvable Points
Human Eye > Bright-field microscope> SEM> TEM (Theoretical) > TEM (Tissue Section) > Atomic force Microscopy
: 1 x 10 ^-1000 in M
Micrometer
1 x 10 – 9000 in M
Nanometer
The most used microscope of students and researchers
Bright-field Microscope (LIGHT)
the one providing source of light
light source
allows you to adjust the intensity of the light coming into the object of interest
condenser lens
holds the microscope slide that you are viewing
stage
further magnify the image that you
see in the ocular lens
objective lens
The eyepiece, where we observe our specimen. Has a magnification of 10x.
Ocular lens
Scanning Total Magnification
4x * 10x = 40x
Low Objective Lens Total Magnification
10x * 10x = 100x
High Objective Lens Total Magnification
40x * 10x = 400x
Oil Immersion (OIO) Total Magnification
100x * 10x = 1000x
enables examination of unstained cells and tissues and is especially useful for living cells
Phase Contrast Microscope (light)
Allows quantification of tissue mass
Interference microscope
Useful for assessing surface properties of cells and other biologic objects
3D Image
Differential Interference Microscope
Object will appear bright in a dark background
Is useful in examining autoradiographs, in which the developed silver grains appear white in a dark background.
Dark-Field Microscope
Clinically it is useful in examining urine for crystals and in demonstrating specific bacteria particularly Treponema pallidum.
Beneficial in Microbiology: allow you to appreciate the shape of the bacteria (rods or curve rods shape) and their movements.
Dark-field Microscope
Indicator of syphilis
Treponema pallidum
is a sexually transmitted infection (STI) that can cause serious health problems without treatment.
Syphilis
Indication of cystinuria
Piatos like appearance of crystals
Cysteine Crystals
is an inherited disease that causes stones made of the amino acid cystine to form in the kidneys, bladder, and ureters.
Cystinuria
Used to display autofluorescent molecules (Fluorochromes) such as vitamin A and some neurotransmitters
Fluorescence Microscope
act as stains to view antibody and antigen complex
Fluorochromes
Widespread application is in the detection of antigens or antibodies in immunocytochemical staining procedures
Antibodies can either be polyclonal or monoclonal to detect antigens in the tissue.
Fluorescence Microscope
-Tolerant to antigen epitope change since these heterogenous antibodies are directed against different types of epitopes in an antigen.
-prone to cross-reactivity
Polyclonal
More specific than polyclonal antibodies. Monoclonal antibodies are binding specific or single epitope type in an antigen unlike with polyclonal antibodies.
-with minimal or less chance of cross-reactivity.
Monoclonal
The direct fluorescence antibody test of brain tissues from animals suspected to be infected with rabies.
Positive dFA: Apple green fluorescence
Negative dFA: No bright objects
- the one utilized to detect the
presence of rabies antigen in the tissues. This is particularly called Anti-rabies Antibodies
Reagent antibodies
against the rabies antigen
Anti-rabies antibodies
utilized to label the antibodies to visualize if there is really a binding that happened.
Fluorochromes
if the antigen is present in the tissue. Indicating infection of rabies.
There is a binding
if there is no antigen present in the tissue.
There will be no binding
Orange fluorescence
Acridine Orange
Yellow fluorescence
Auramine O
Bright red fluorescence
Rhodamine B
Apple green fluorescence
Fluorescein Isothiocyanate (FITC)
Using one antibody to detect antigen.
Direct Fluorescence Assay
Using two antibodies to detect antigen
Indirect Fluorescence Assay
Allows visualization of a biologic specimen in three dimensions (3D configuration)
It combines components of a light optical microscope with a scanning system to dissect a specimen optically allowing you to visualize the minute organism
Confocal Scanning Microscope
uses quartz lenses with an ultraviolet light source.
The image depends on the absorption of UV light by molecules in the specimen
Ultraviolet Microscope
may achieve a resolution of 0.1 m and resembles the workings of a spectrophotometer;
results are usually recorded photographically.
is useful in detecting nucleic acids, specifically the purine and pyrimidine bases of the nucleotides
Ultraviolet Microscope
It is also useful for detecting proteins that contain certain amino acids
Also use to determine quantitatively the amount of DNA and RNA in individual cells.
Ultraviolet Microscope
Identify crystals to identify the exact dxs
It uses the fact that highly ordered molecules or arrays of molecules can rotate the angle of the plane of polarized light
Polarizing Microscope
(POLARIZING MICROSCOPE)
located Between the light source and the specimen.
Polarizer
(POLARIZING MICROSCOPE)
located between the Ocular and the
Objective lens.
Analyzer
has an additional feature as compared to the Light microscope. Which is the addition of 11 filters
Polarizing Microscope
can provide morphologic and analytic data on cells and tissues:
Electron Microscope
Two kinds of EMs
Transmission electron microscope (TEM)
Scanning electron microscope (SEM)
uses the interaction of a beam of electrons with a specimen to produce an image. Enables you observe structures found in the inner portion of the organism, it’s organelles.
Transmission Electron Microscope
[T for through (nakikita through the specimen)
Transmission Electron Microscope
the electron beam does not pass through the specimen but is scanned across its surface. Allows you to appreciate its appendages.
Scanning Electron Microscope
[S is for surface (nakikita lang surface ng specimen)
Scanning Electron Microscope
PREPARATION OF TISSUES FOR STUDY
Fixation
Dehydration
Clearing
Infiltration
Embedding
Trimming
Section-Cutting
Staining
Mounting
Labeling
To preserve cell and tissue structure in a life like manner.
Small pieces of tissues are immersed in a solution called fixative after removal from the body
Fixation
best general fixative
10%neutral buffered formalin
Self Digestion
Autolysis
Preserve tissue in a life-like manner
To avoid tissue digestion by enzymes present within the cells or bacteria
Fixation
Fixative ratio
20:1
Remove intracellular and extracellular water. To prepare it in absorbing solutions used in subsequent steps
Tissue is transferred through a series of increasingly concentrated alcohol solutions called as dehydrating agents , ending in 100%, which removes all water
Dehydration
Most common series (DEHYDRATION)
70%, 95%, 100% (absolute alcohol)
Small specimen (DEHYDRATION)
30% - pataas
Why is it in an increasing concentration? (DEHYDRATION)
to avoid tissue distortion
most commonly used alcohol in dehydration
Ethanol (Ethyl Alcohol)
Also known as Dealcoholization
removal of alcohol from the tissue
Clearing