Reviewer Questions Answered Correctly.
Preparation of tissue section - Answer Most common procedure used in histologic research is the? this
can be examined visually through transmitted light
ideal microscopic preparation - Answer it is preserved so that the tissue on the slide has the same
structural features it had in the body
Fixative - Answer To preserve tissue structure and prevent degradation by enzymes released from the
cells or microorganisms, pieces of organs are placed as soon as possible after removal from the body in
solutions of stabilizing or cross-linking compounds called
fixation - Answer tissues are usually cut into small fragments before ___________ to facilitate
penetration.
formalin - Answer One widely used fixative for light microscopy is
Glutaraldehyde - Answer a fixative used for electron microscopy
dehydration - Answer Before infiltration with such media, the fixed tissue must undergo ___________
by having its water extracted gradually by transfers through a series of increasing ethanol solutions,
ending in 100% ethanol.
clearing - Answer it is where alcohol is removed in organic solvents in which both alcohol and paraffin
are miscible
xylene - Answer organic solvent used in clearing stage
infiltration - Answer this is when tissue is then placed in melted paraffin in an oven at 52-60 degrees
celcius until it becomes completely infiltrated with substance
, embedding - Answer The paraffin-infiltrated tissue is placed in a small mold with melted paraffin and
allowed to harden
trimming - Answer The resulting paraffin block is trimmed to expose the tissue for sectioning (slicing)
on a microtome.
microtome - Answer an instrument that cuts paraffin blocks thinly
staining - Answer Most cells and extracellular material are completely color- less, and to be studied
microscopically tissue sections must undergo
basophilic - Answer Cell components, such as nucleic acids with a net negative charge (anionic), have
an affinity for basic dyes and are termed
acidophilic - Answer cationic components, such as proteins with many ionized amino groups, stain
more readily with acidic dyes and are termed
hematoxylin and eosin (H&E) - Answer Of all staining methods, the simple combination of __________
and ____________ is used most commonly.
counterstain - Answer eosin is considered a ____________, which is usually a single dye applied
separately to distinguish additional features of a tissue.
periodic acid-Schiff (PAS) reaction - Answer it utilizes the hexose rings of polysaccharides and other
carbohydrate-rich tissue structures and stains such macromolecules distinctly purple or magenta
sudan-black - Answer used for lipid staining
12 hours to 2 1⁄2 days - Answer Slide preparation, from tissue fixation to observation with a light
microscope, may take from ___________________, depending on the size of the tissue, the embedding
medium, and the method of staining.