Histopath (Qual Controls, Fresh tissue Examination & Fixatives Flashcards
A method of Fresh tissue examination whereby a selected tissue specimen is immersed in a watch glass containing a solution, carefully dissected and examined under the microscope
teasing or dissociation
What is the solution referred in teasing or dissociation method of examining fresh tissue
isotonic salt solution
T/F. In Squash Preparation, how many mm in diameter are placed in a microscopic slide
not more than 1 mm
What action is allowed to be absorbed by the tissue when vital stain is placed at the junction of the slide and the cover glass
Capillary Action
Enumerate the 4 methods of Fresh tissue examination
Teasing or Dissociation
Squash Preparation
Smear Preparation
Frozen Section
It is the process of examining sections or sediments, whereby cellular materials are spread lightly over a slide by means of a wire loop or applicator, or by making an apposition smear with another slide
Smear Preparation
A methods of fresh tissue examination that is especially useful in cytologic examinaTIONS, particularly cancer diagnosis
Smear preparation
What are the types of smear preparation
pull-apart
streaking
spreading
touch preparation or impression smear
A type of smear preparation where applicator stick or platinum loop is used, the material is rapidly and gently applied in a direct or zigzag line throughout the slide, attempting to obtain a relatively uniform distribution of secretion
streaking
T/F. In Spreading type of Smear preparation, too thin or too thick smears have to be avoided, since they make the tissues unsuitable for examination
false. streaking
A type of smear prep whereby a selected portion of the material is transferred to a clean slide and gently spread into a moderately thick film by teasing the mucous strands apart with an applicator stick
spreading
This method is a little more tedious than streaking, but has the advantage of maintaining cellulat interrelationships of the material to be examined
spreading
What type of smear preparation where it is recommended for smear preparations of fresh sputum and bronchial aspirates ans also for thick mucoid secretions
spreading
it is done by placing a drop of secretions or sediment upon one slide and facing it to another clean slide
pull-apart
What type of smear preparation that is uyseful for preparing smears of thick secreations such as serous fluid, concentrated sputum, enzymatic lavage samples from GI tract and blood smears
pull- apart
A special method of smear preparation whereby the surface of a freshly cut piece of tissue is brought into a contact and pressed on to the surface of a clean glass slide; allowing the cells tp be transferred directly to the slide
touch preparation or impression smear
Impression smear is examined by ________________ and stained by _____________________
phase contrast microscopy
light microscopy study
this method is normally utilized when a rapid diagnosis of the tissue in question uis required.
frozen section
What elements are to be demonstrated when frozen sections are recommended
LIPIDS AND NERVOUS ELEMTNS
What is the temperature of a cryostat in forzen sections
-10 to -20 degree celsius
What is the thickness of a fresh forizen tissue
10 to 15 microns
T/F. fresh frozen tissues must always be in a very thin slices that is cut from a microtime with carbon dioxide
true
T/F. tissue for freezing should be fresh and freezing can be done slowly to avoid distortion of tissue
false.
tissue for freezing should be fresh and freezing should be done as quickly as possible. slow freezing can cause distortion of tissue d/t ice crystal artifacts
enumerate the most commonly used method of freezing
liquid nitrogen
Isopentane cooled by liquid nitrogen
carbon dioxide gas
aerosol sprays
Identify what is the method of freezing is being described below:
generally used in histochemistry and during operative procedures
liquid nitrogen
Identify what is the method of freezing is being described below:
the most rapid of the commonly available freezing agents
liquid nitrogen
Identify what is the method of freezing is being described below:
main disadvantage is that soft tissue is liable to crack d/t rapid expansion of the ice wthin the tissue, producing ice crystals or freeze artifacts
liquid nitrogen
T/F. the tissue snap-frozen in liquid nitrogen must therefore be allowed to equilibrate to cryostat chamber temperature before sectioning is attempted
true
T/F. the majority of non-fatty unfixed tissues are sectioned well at temp between -10 to -25 degree celsius
true
Identify what is the method of freezing is being described below:
causes a vapor phase
liquid nitrogen
One problem with the use of liquid nitrogen is it cause vapor phase. To overcome this problem, it needs to freeze the tissue in ___, ___, ____ that has a high thermal conductivity
isopentane
OCT
frozen 2.2
Identify what is the method of freezing is being described below:
increasingly popular in recent years, and is adequate for freezing small pieces of tissue excapt muscle
AEROSOLS SPRAYS
Identify what is the method of freezing is being described below:
A pyrex of glass beaker is usally suspended in a flask of liquid nitrogen until half-liquid and half-solid stage is reached
isopentane
Enumerate in order on how we preserved and processed solid structures and tissues
fixation
dehydration
clearing
infiltration(impregnation)
embedding
trimming
section-cutting
staining
mounting
labeling
the first and most criticsl step in histotechnology
fixation
a mechanism in fixation whereby chemical of the fixative is taken in and becomes part of the tissue giving stability to the protein
additive
a mechanism in fixatives whereby fixing agent is not incorporated into the tissue
non-aaditive fixation
a mechanism in fixatives that involves removing of water that bound to H-bonds
non-aaditive fixatives
What are the 6 main factors involved in fization?
hydrogen Ion concentration
temperature
thickness of section
osmolality
concentration
duration of fixation
What are the Practical consideration of fixation
speed
penetration
volume
duration of fixation
T/F. recommended size of tissue is 2 cm2, and no more than 4 mm thick
true
T/F. refrigeration is used to slow down decomposition if the tissue needs to be photographed and cannot be fixed immediately
true
What type of fixative accdg. to action that permit the general microscopic study of tissue structures without altering the structural pattern and normal intercellular relationship of the tissue in question
microanatomical fixatives
What type of fixative accdg. to action that preserve specific parts and particular microscopic elements of the cell itself
cytological fixatives
A fixatives that usually contain glacial acetic acid as their perimary component. They have a pH of 4.6 or less
nuclear fixatives
T/F. Cytoplasmic fixatives must have a glacial acetic acid. They have a pH of more than 4.6
false. must not have glacial acetic acid since it can destroy mitochondria and golgi bodies
Two aldehyde fixative mixtures have bee particularly useful for electron cytochemistry. What is the best know solution?
Karnovsky’s paraformaldehyde-glutaraldehyde solution
What is the aldehyde which has been introduced as a mixture with glutaraldehyde or formaldehyde
acrolein
One of the most widely used fixatives that is made from formaldehyde
10% formalin
T/F. high formaldehyde concentrates tend to overharden the outer layer of the tissue and affect staining adversely
true
