Histology and its Methods of Study Flashcards
(18 cards)
Two types of electron microscopes
transmission, scanning
9 steps in slide preparation
1) tissues are obtained and cleaned 2) chemically fixed 3) processed (dehydrated and cleared) 4) embedded in paraffin 5) sectioned with a microtome 6) mounted on a slide 7) de-paraffinized and rehydrated 8) stained 9) coverslipped
3 types of fixatives
1) aldehydes 2) alcohols 3) oxidizing agents ex/ KMnO4
how is a slide processed after being fixed?
1) dehydrated via alcohol exposure 2) alcohol is replaced with xylene 3) slide is infiltrated with paraffin embedding agent
how is a slide rehydrated after being mounted?
-opposite order of dehydrating! 1) remove the paraffin 2) expose slide to xylene 3) replace xylene with alcohol 4) replace alcohol with water
toluidine blue, hematoxylin and methylene blue are all examples of ____ stains
BASIC STAINS
Orange G, eosin and fuchsin are all examples of ___ stains
ACIDIC stains
Osmium tetroxide is good at visualizing:
adipose and fatty substances
What kind of stain was used for this?
Osmium Tetroxde: good at visualizing fat droplets
What tissue type is this (left)? What are the two layers called (left pic)? What kind of stain was used to visualize this?
What kind of stain was used on the right? What kind of structures is this stain good at differentiating?
Left: Muscle tissue (smooth) with two layers; an outer longitudinal and an inner circular layer that allows it to move in graded fashion/peristaltic manner. Normal Hemotoxylin and Eosin stain used
Right: also muscle tissue. This time, TRICHROME STAIN was also used. Differentiates between collagenous fibers and basophilic structurs, allows you to see the connective tissues that attah fasciles together. Ex/ paramycium ,endomycium etc.
What kind of stain is used here? What type of tissue is this?
This is nervous tissue. SILVER stain used
Name and purpose of this staining? What does it have affinity for?
Periodic Acid-Schiff stain (PAS). Good for visualizing microvilli brush boarder and goblet cells. Often counter stained with hemotoxylin. Also has high affinity for GLYCOPROTEINS
What kind of stain is used here? Purpose?
Giesma stain. Good for visualizing white blood cells and general blood components. Differentiates cytoplasms, granules, and nuclei of cells
What is immunihitochemistry?
Specific interactions between lantibody and antigen to allow precise identification, localization, and in some cases, quantification of cellular components (usually proteins)
Examples of cellular inclusions
fat droplets, glycogen granules, lipofuschin pigment
List other histological techniques that allow for visualization in addition to staining
1) immunohistochemistry
2) frozen sections: freezing sections in liquid nitrogen for fast cutting and staining. Good when you need to know histo results ASAp
3) electron microscopy tissue prep: fized with osium and embedded in plastic rather than paraffin. Allows for embedding of thinner sections.
Hemotozylin has affinity for ___ acids, and eosin is an ___ dye with an affinity for ___ cytoplasmic components of the cell.
Hemotozylin has affinity for NUCLEIC acids, and eosin is an ACIDIC dye with an affinity for BASIC cytoplasmic components of the cell.
The golgi method is a specific type of ___ staining that specifically brings out ___
specific type of silver staining that brings out PYRAMEDAL NEURONS
