Free Histotechnologist Practice Test
1. Which of the following methods could be used to remove mercury pigment, a fixation artifact?
a. Treat the specimen with an iodine solution followed by bleaching with sodium thiosulfate
b. Treat the specimen with saturated alcoholic picric acid
c. Treat specimen with 10% ammonium hydroxide in 70% ethyl alcohol
d. Treat the specimen with 1% acid alcohol
2. In humans, binucleated cells can be found in healthy _______ epithelium.
a. stratified cuboidal
b. stratified squamous keratinizing
d. simple columnar
3. Chromatolysis, as demonstrated by the cresyl echt violet method, is a sign of which of the following?
a. Injury of a neuron
b. Proliferation of astrocytes
c. Loss of myelin sheath
d. Activation of microglia
4. Which of the following stains is the BEST for demonstrating reticular fibers in a paraffin section?
a. Rhodizonate method
c. Gomori stain
d. Giemsa stain
5. A technician stains a tissue suspected to have a liposarcoma by the Oil Red O method. No positive red staining is visualized, which is unusual since most tissues contain some fat. What could be one explanation for this result?
a. Oil Red O stock was dissolved in isopropyl alcohol rather than propylene glycol.
b. A frozen section was used rather than a paraffin section.
c. An alcohol fixative was used.
d. A 10% neutral-buffered formalin was used.
Answers & Explanations
1. A: Mercury pigment can be removed by treating the specimen with an iodine solution followed by bleaching with sodium thiosulfate. Formalin pigment and malarial pigment can both be removed by either treating the specimen with saturated alcoholic picric acid or by treating the specimen with 10% ammonium hydroxide in 70% ethyl alcohol. Chromic oxide pigment can be removed using 1% acid alcohol.
2. C: Transitional epithelium lines the urinary tract. It is specialized to accommodate a large degree of stretching and to withstand the toxicity of urine. It is made up of 4 to 5 layers of cells. The basal cells are nearly cuboidal. The middle layers of cells are polygonal, and the cells along the lumen are rounded and sometimes contain two nuclei.
3. A: The cresyl echt violet method is used to visualize the Nissl substance of neurons. Nissl bodies stain darkly because of the high rough endoplasmic reticulum content, which contains RNA. Injury of a neuron causes the Nissl substance to disappear. This pathological change is referred to as chromatolysis.
4. C: Reticular fibers are fine fibers that provide a mesh framework for the more cellular organs such as the spleen, liver, and lymph nodes. By the Gomori method, potassium permanganate is used to oxidize the hexose sugars of reticulin fibers to aldehydes. Ferric ammonium sulfate is then used as a sensitizer, which is then replaced by silver. Formalin is used to reduce the silver to its visible form.
5. C: The Oil Red O method is used to detect neutral lipids. Alcohol fixatives can dissolve lipids, so using an alcohol fixative could result in a false-negative result.
Last Updated: 07/05/2018