H284 Homework Questions
In the Hotchkiss-McManus PAS technique, polysaccharides present in fungal walls are oxidized to aldehydes by 1% periodic acid 0.5% periodic acid 5% chromic acid 4% chromic acid
1% periodic acid
Spirochetes are filamentous bacteria that are known to be argentophilic argyrophilic polychromatic metachromatic
argyrophilic
at what thickness are sections cut for RNA analysis?
10 um
The recommended fixative for tissue suspected of containing spirochetes is 10% neutral buffered formalin Bouin solution Zenker solution Helly fluid
10% neutral buffered formalin
In the Brown-Hopps stain for bacteria, one of the differentiators is acid alcohol 95% ethanol Correct! Gallego solution 70% ethanol
Gallego solution
The primary dye used in rapid, non silver procedure to demonstrate cysts of Pnuemocystis carinii is Giemsa basic fuchsin Schiff reagent carbol-fuchsin
Giemsa
Of the following, the most informative special stain for demonstrating bacteria in tissue sections is the Gridley Gram Grocott Warthin-Starry
Gram
The Gridley stain uses periodic acid and methenamine silver periodic acid and Schiff reagent chromic acid and methenamine silver chromic acid and Schiff reagent
chromic acid and Schiff reagent
Individual virus particles cannot be seen by light microscopy, but can be visualized by phase microscopy polarizing microscopy electron microscopy fluorescence microscopy
electron microscopy
The naphthol AS-D chloroacetate esterase demonstrates: granulocytes plasma cells mitochondria motor end plates
granulocytes
All are synonyms for the antigen binding site in an antibody, EXCEPT Fab Variable region heavy chain light chain
heavy chain
The following are common fluorochromes used in IHC, EXCEPT: FITC Texas Red Rhodamine Horseradish peroxidase
horseradish peroxidase
The most commonly used phenolic compound for reducing absorbed silver to a visible metallic state in argyrophilic procedures, such as the Warthin-Staryy, is sodium thiosulfate uranyl nitrate hydroquinone sodium bisulfate
hydroquinone
The basic structure of filamentous fungi is the hypha bud endospore spherule
hypha
The difference between Cryptococcus neoformans and other yeast-like fungi is that only Cryptococcus neoformans has a capsule containing glycogen mucin aldehydes lipid
mucin
polyclonal antibodies recognize _____ epitopes from ______ antigen
multiple, a single
The carbol-fuchsin methods are specific for: mycobacteria dimorphic fungi diplococci spore-forming bacilli
mycobacteria
The auramine-rhodamine technique will demonstrate Staphylococcus aureus Mycobacterium tuberculosis Candida albicans Clostridium tetani
mycobacterium tuberculosis
Which colored end product is insoluble in alcohol? New fuchsin Fast red Fast blue FITC
new fuchsin
monoclonal antibody preparations contain _______ of antibody derived from a ______ clone B cell. Consequently, they are _______ for a single epitope
only one type, single, highly specific
Microscopic evaluation of a Brown & Brenn-stained controlled section shows the presence of gram-positive organisms, but no gram-negative organisms. The most likely cause is -too little time in iodine solution -overdifferentiation in Gallego solution -overdifferentiation in picric acid-acetone solution -too little time in crystal violet solution
overdifferentiation in picric acid-acetone solution
While examining a GMS-stained section microscopically, it is noted that elastin, crenated red cells and mucin have stained black, confusing interpretation. This is most likely caused by overexposure to hot silver nitrate underexposure to gold chloride underexposure to sodium thiosulfate performing the procedure in a microwave oven
overexposure to hot silver nitrate
The periodic acid-Schiff (PAS) procedure for fungi works on the underlying principle of the argyrophilic nature of fungi argentophilic nature of fungi oxidation of mucopolysaccharides in fungal walls affinity of ketone groups for Schiff reagent
oxidation of mucopolysaccharides in fungal walls
The PAS stain differs from Gridley technique in the use of Schiff reagent component demonstrated oxidizer used sections required
oxidizer used
list 5 factors that influence enzyme demonstration
pH temperature concentration inhibitors activators
In the Hotchkiss-McManus modifications of the PAS technique, aldehydes are formed by periodic acid chromic acid potassium permanganate sodium bisulfate
periodic acid
Which chromogen yields a crisp, insoluble, stable, dark brown reaction product? AEC Fast Red New fuchsin DAB
DAB
The following are the 2 most common horseradish peroxidase chromogens used in IHC HRP, DAB DAB, AEC AEC, Fast Blue Fast Red, Fast Blue
DAB, AEC
Microscopic inspection of PAS-stained control section for fungi reveals overstaining of the entire section, making identification of fungal elements difficult. A likely cause for this problem is the use of periodic acid oxidizer chromic acid oxidizer an incorrect reducing agent an incorrect counterstain
periodic acid oxidizer
Amebas can be demonstrated with H&E stain and the Grocott methanamine silver procedure Kinyoun acid-fast procedure Vassar-Culling procedure periodic acid-Schiff procedure
periodic acid-Schiff procedure
monoclonal or polyclonal: more sensitive
polyclonal
monoclonal or polyclonal: recognizes different epitopes from one antigen
polyclonal
monoclonal or polyclonal: produced by multiple B cell clones
polyclonal
monoclonal or polyclonal: prone to false positives (more background staining)
polyclonal
For light microscopic evaluation, it is generally necessary to use special stains to demonstrate fungi in tissue sections because fungi can only be seen using silver impregnation fungi are removed in the routine staining process some fungi do not stain with H&E no fungi stain with H&E
some fungi do not stain with H&E
antibody
sometimes called immunoglobulin, is the protein produced by plasma cells in response to antigenic stimulation
The most popular IHC method for most diagnostic laboratories is Avidin-biotin labeling streptavidin-biotin or polymer labeling fluorochrome polymer labeled primary antibody
streptavidin-biotin or polymer labeling
Mycotic diseases that go beyond superficial or cutaneous involvement to affect vital organs in extensivedisease and even death, are referred to as subcutaneous calcific dematiacious systemic
systemic
IHC is used to determine all EXCEPT: How advanced a neoplasm is If tumors grew from epithelial or connective tissues How well a patient may respond to a specific medication the presence of damaged DNA on a tissue sample
the presence of damaged DNA on a tissue sample
If a chromogen produces a colored reaction product that is soluble in alcohol or xylene, the sections will require xylene-base mounting medium the sections will require aqueous mounting medium a peroxidase quench step will be needed a fluorescent microscope will be needed
the sections will require aqueous mounting medium
antigen
the substance in the body that induces a detectable immune response
Which statement define immunohistochemistry? A - Microscopic localization of specific antigens in tissues by staining with antibodies labeled with fluorescent or pigmented material. B - Technique for identifying cellular or tissue constituents (antigens) by means of antigen-antibody interactions, the site of antibody binding being identified either by direct labeling of the antibody, or by use of a secondary labeling method. C - The determination of the number, size, and nucleic acid content of cells D - A technique that uses a labeled complementary DNA, RNA or modified nucleic acids strand to localize a specific DNA or RNA sequence in a portion or section of tissue, in cells, and in circulating tumor cells. A and B are correct A, B, and C are correct B and D are correct all options are correct
A and B are correct
Which of these elements cannot be demonstrated by H&E, therefore requiring enzyme histochemical techniques? A - changes in muscle fiber size B - Changes in location and appearance of muscle fiber nuclei C - Presence of inflammatory cells D - Increase in connective tissue E - Fiber type grouping F - Fiber type predominance G - Central core disease (target fibers) -B through F are correct -A through G are correct -A through D are correct -E, F, and G are correct
E, F, and G are correct
Which is the area of the antibody that binds with the antigen? Fc or constant region Fab or variable region stem region Hinge region
Fab or variable region
The most consistently reliable technique for demonstrating fungi in tissue is the PAS Gridley method for fungi Grocott's methenamine silver (GMS) Ziehl-Nelson
Grocott's methenamine silver (GMS)
At pH 9.4, Type _____ fibers stain light
I
At pH 9.4, Type ______ fibers stain dark
II
What is the most common antibody produced by the immune system? IgA IgM IgG IgE
IgG
what disease does phosphorylase stain help diagnose?
McArdle disease
Entamoeba histolytica can be demonstrated well with this procedure Gordon-Sweet Kossa PAS Schmorl
PAS
In the Gridley procedure, the aldehyde fuchsin stain will attach to aldehydes Schiff reagent chromic acid periodic acid
Schiff reagent
This staining procedure is probably the most appropriate method for demonstrating acid fast organisms that are difficult to stain by other methods Ziehl-Neelsen Gridley Kinyoun Wades modification of Fite's
Wades modification of Fite's
the primary antibody is raised against ________ while the secondary antibody is raised against __________
a target antigen, the Fc portion of the primary antibody host species
The property on which the acid-fast stain depends is the organisms': affinity for basic dyes capability for reducing silver failure to stain with a dye other than basic fuchsin ability to resist decolorization with dilute acids
ability to resist decolorization with dilute acids
In order for the Gram stain to work properly, it is important to apply the mordant after the primary dye before the primary dye in the same solution as the primary dye after counterstaining
after the primary dye
Important factors affecting gram-positive staining of some organisms include the -age of organisms and presence of liquid capsule -age and size of organisms -time in crystal violet and safranin solution -time in 0.5% periodic acid
age of organisms and presence of liquid capsule
Acid alcohol decolorizers are generally recommended over aqueous ones for use with "acid-fast" procedures because -alcoholic solutions penetrate more rapidly -alcoholic solutions penetrate more slowly -aqueous solutions are less stable -alcoholic solutions allow more uniform decolorization
alcoholic solutions allow more uniform decolorization
Fc
also known as the heavy chain or fixed domain, is the area of the immunoglobulin molecule that activates the compliment
Fab
also known as the light chain or variable domain, refers to the area of the antibody molecule that determines the the binding capacity of the molecule
The methylene blue counterstain is too heavy on the Kinyoun acid-fast stain, so that the organisms present are very difficult to locate. This problem could most likely be corrected by: cutting a new section and repeating the stain increasing the amount of light used for microscopic examination backing the section up into acid-alcohol, then recounterstaining removing the coverslip and repeating the entire procedure.
backing the section up into acid-alcohol, then recounterstaining
In the Taylor's Brown and Brenn modification of the Gram stain for tissues, gram-positive organisms appear: bright red blue-black yellow-orange green
blue-black
The differential staining achieved with the Gram stain is due to differences in the bacterial: size shape cell wall nucleus
cell wall
During microscopic examination of fungus stain, extraneous fungal elements are seen above rather than in the section. The most likely cause for this problem is poor dehydration prior to coverslipping too long exposure to silver solution Correct! contaminated staining solutions a bacterial rather than fungal disease
contaminated staining solutions
A fungus disease characterized by pleomorphic yeast cells, narrow-based budding and carminophilia is Leishmaniasis cryptococcosis histoplasmosis candidiasis
cryptococcosis
When the mucoid capsule of this fungus is intact, Mayer's mucicarmine may be used for its demonstration blastomyces histoplasma cryptococcus prototheca
cryptococcus
at pH 4.6, Type I fibers stain ___
dark
Antibodies are produced by differentiated B lymphocytes activated T lymphocytes Macrophages Opsonization
differentiated B lymphocytes
Tissue for some enzyme demonstration should be fixed if possible because diffusion artifact is decreased enzyme activity is enhanced a wider range of temperatures can be used the concentration of the substrate is less critical
diffusion artifact is decreased
The chromic acid keeps turning dark after using only two or three time. This could most likely be corrected in the future by allowing more time in the xylene increasing the time in the alcohols checking the concentration of the chromic acid solution ensuring the complete removal of alcohol prior to chromic acid
ensuring the complete removal of alcohol prior to chromic acid
The main purpose of ATPase staining of muscle at different pH's is to demonstrate:
enzymatic activity and to distinguish the fiber types
A carcinoma is a tumor originated from Epithelial cells Mesenchymal tissue Connective tissue fibers Lymphoid tissue
epithelial cells
True or False: Epitopes have specific areas for antigen binding called antibodies True Correct! False
false
Which one can be used as alkaline phosphatase chromogen in IHC? DAB AEC HRP Fast blue
fast blue
The purpose of iodine in Gram procedures for staining bacteria is to make cell walls of bacteria permeable form a dye-lake with primary crystal violet stain decolorize crystal violet inactivate bacteria
form a dye-lake with primary crystal violet stain
Disease process known as "mycoses" belong to this specific classification of microorganisms bacteria viruses fungi protozoa
fungi
Filamentous structures known as "hyphae" are associated with the following microorganisms bacteria protozoa viruses fungi
fungi
Lung sections showing granulomatous inflammation on H&E stained sections are commonly stained with at least two techniques to demonstrate the presence of fungi or acid-fast organisms fibrosis or acid-fast organisms fungi or muscle fungi or fibrosis
fungi or acid-fast organisms
Artificial precipitate seen in the Grocott stain may be the result of using plastic forceps gelatin in the water bath glassware that was not chemically clean excess time in the gold chloride solution
glassware that was not chemically clean
Which of the following species are commonly used as a host for producing polyclonal antibodies? oysters dogs peacocks goats
goats
An organism that is resistant to decolorization after staining with a basic aniline dye followed by an iodine mordant, is referred to as acid-fast argentaffin gram-positive argyrophilic
gram positive
In IHC, the quenching step is used: In order to avoid false positive or background staining due to endogenous peroxidase activity In order to block the primary antibody from binding nonspecific proteins In order to avoid false positive or background staining due to endogenous ALP activity In order to unmask epitopes crosslinked by formalin
in order to avoid false positive or background staining due to endogenous peroxidase activity
Fresh silver solutions were properly prepared and used in a Warthin-Starry technique. After completion of the procedure, a positive control does not demonstrate spirochetes. Of the following, the most likely reason for this problem is poor fixation contaminated glassware incorrectly prepared reducing solution incorrectly selected mordant
incorrectly prepared reducing solution
A labeled secondary antibody is used in which IHC method? PAP Direct method Indirect method AP-AAP
indirect method
chromogen
is the compound used to produce a specific color reaction in the staining procedure
at pH 4.6, Type 2A fibers stain
light
The property of " acid-fastness" appears to be related to the presence of this substance in the walls of organisms lipids protein amyloid iron
lipid
When monocytes migrate from the circulation into the tissues, they differentiate into: fibroblasts plasma cells macrophages lymphocytes
macrophages
A sarcoma is a tumor originated from Epithelial tissue Correct! Mesenchymal tissue Connective tissue fibers Lymphoid tissue
mesenchymal tissue
The main diagnostic tools in traditional pathology are autopsy, histology, cytology and more recently [1] to diagnose and classify diseases. radiography IHC molecular biology proteomics
molecular biology
monoclonal or polyclonal: lower lot-to-lot variability
monoclonal
monoclonal or polyclonal: more specific
monoclonal
monoclonal or polyclonal: raised against one specific eptiope
monoclonal
monoclonal or polyclonal: produced by a single B cell clone
monoclonal
monoclonal or polyclonal: prone to false negatives
monoclonal
Hybridomas are used in the production of polyclonal antibodies monoclonal antibodies target antigens wash buffers
monoclonal antibodies
Melanin and other pigments in tissue may interfere with spirochete identification in Warthin-Starry procedures. Modifications in the staining procedure that might eliminate this problem are prolonged development and a lower pH prolonged development and a higher pH shorter development and a lower pH shorter development and a higher pH
prolonged development and a lower pH
The definition of "Antigens" is: proteins or monosaccharides that inhibit an immune response proteins or monosaccharides that induce an immune response synthetic drugs injected in mice in order to develop hybridoma the product of cells from a hybridoma merged plasma cells
proteins or monosaccharides that induce an immune response
primary antibody
reacts with a specific target antigen and is the initial antibody used in the protocol
When using Fite procedure for staining Mycobacterium leprae, acid fast organisms are stained ___________ with a blue background: blue to purple orange to red red to violet green to yellow
red to violet
background
refers to the non-specific staining that covers or masks specific areas of staining
quenching
refers to the step of the IHC procedure that surpresses endogenous peroxidase activity that would cause non-specific reactivity with the chromogen
In acid-fast staining, drying the section after the carbol-fuchsin solution leads to the formation of insoluble compounds that are resistant to decolorization. This should be avoided because it may: hint:If those compounds form, the technician might try to decolorize it for a longer time in an effort to remove the pigment, which will lead to... (choose your answer) Correct! result in decolorization of acid-fast organisms hydrochloric acid prevent decolorization result in acid-fast organisms that appear "beaded"
result in decolorization of acid-fast organisms
(T/F) In the direct IHC method, there is no need for a secondary antibody.
true
Even though tissue for enzyme demonstration should be fixed, muscle biopsies are frozen and unfixed. True False
true
In the indirect IHC method, the primary antibody is: conjugates with a flourochrome conjugates with an enzyme unconjugated conjugated with strepavidin
unconjugated
In a piece of tissue stained with Warthin-Starry technique, the spirochetes appear yellow. The most likely cause of this problem is overdeveloping underdeveloping use of impure reagents improper pH
underdeveloping
When using a Fite procedure, in order to protect the leprosy organism from acid-fast component extraction, the section may be deparaffinized in xylene and peanut oil xylene and dioxane xylene and alcohol xylene and acetone
xylene and peanut oil
