Lecture 2 Staining Flashcards
Why is it important to stain?
Overcome a lack of contrast in tissue Identify cell types and cellular structures Identify specific molecules within a tissue (clinical diagnostics)
Tissues that stain with a basic stain are ______.
basophilic
What are components which are basophilic?
Nuclei or RER in secretory cells
Tissues that stain with an acidic stain are _____.
Acidophilic
What are components which are acidophilic?
“normal” cytoplasm
What are examples of basic dyes?
Methyl green, Methylene blue, Pyronin G (red), Toluidine blue, Hematoxylin
What type of stain is this, what are the different structure being stained?
H&E
nuclei = blue (basophilic) → Hematoxylin
cytoplasm = pink (acidophilic) → Eosin
Most carbohydrates react with ______ to produce aldehydes, which convert the colourless ______ reagent (Basic Fuchsin) to pink, or magenta.
Periodic acid, Schiff, PAS stain
What are examples of tissues that stain well with PAS?
Glycogen, mucin, elastic fibers, reticular fibers, basement membranes, thyroid colloid, basophilic granules in the pituitary gland, and other polysaccharides such as the ground substance of cartilage are stained fuchsia or pink.
Enzyme digestion with diatase would stain well with?
PAS
_____ is used to stain an extracellular matrix after a nuclear and cytoplasmic stain has been used (H&E).
Mallory’s trichrome
This is an example of what stain, what is the blue structure?
Mallory’s trichrome, collagen
What is a “change of colour stain” and what are examples?
metachromatic
Azure, toluidine blue
Mast cells (mediators of inflammation) stain purple in an otherwise blue background is an example of what class of stain?
metachromatic
______ dye combination stains chromatin shades of purple and cytoplasm and collagen a lighter violet.
Pararosaniline-toluidine blue (PT)
True or False: PT satins do not penetrate plastic sections like H&E.
False, they do
______ embedded sections to provide better detail of cell and tissue structures.
Resin
______ is also commonly used for differential staining of cellular components, particularly ______.
Toluidine blue, cytoplasmic granules
______ use azure blue stains to stain White Blood Cell granules basophilic or neutrophilic, used with eosin for RBC and eosinophilic WBC, and methylene blue stains nuclei.
Wright-Giemsa stain
______ is used to trace nerves, stain Golgi, reticular fibers
Silver impregnation
What is better for paraffin processing or cryosections when staining lipids?
Cryosections, b/c paraffin will extract lipids (just like droplets)
What are the 3 lipid/fat stains?
Sudan Black
Sudan IV (red)
Congo Red
______ is used to fix lipids.
Osmium tetroxide
How are functioning enzymes viewed in a stain?
A specific enzyme-catalyzed reaction is performed with the section and the reaction product is visualized as an insoluble precipitated on the section.
______ fluorescently stains nucleic acids orange.
Acridine orange
______ binds DNA and ______ binds actin in flurescent microscopy.
DAPI (4’,6-diamino-2-phenylindol, fluorescein-phalloidin
______ are tissue preparations in which particles called silver grains to indicate the cells or regions of cells in which specific macromolecules were synthesized just prior to fixation.
Autoradiography
How does in situ hybridization work?
The section is incubated with digoxigenin-labeled complementary DNA (cDNA) probe for the HPV DNA, ISH of this tissue section reveals that many cells (brown) contain the human papillomavirus (HPV).
What type of immunochemistry is more common, sensitive and has better control?
Indirect
What does this picture show?
Indirect Immunolocalization of the filament protein desmin in a single cultured uterine cell. Nucleus stained with DAPI
______ of light at a lower wavelength. ______ of light from the fluorophore at a higher wavelength Difference is ______.
Excitation, Emission, stokes shift
True or False: Multiple fluorophores can be viewed in the same section
True
What types of microscopy can produce 3D images? And what are the benefits to it?
Confocal microscopy
Reduced blurring of the image from light scattering
Increased effective resolution
Improved signal to noise ratio
Clear examination of thick specimens
What two metals are used in TEM staining?
1) Uranyl Acetate
2) Lead citrate
True or False: IHC and ISH important in clinical diagnostics
True
