FREE CSMLS Histotechnology and Microbiology Questions and Answers
Which of the following factors is a possible cause for cocci in chains to appear pink on a gram stain?
Explanation:
Antibiotic use can affect the cell wall of bacteria, leading to altered staining characteristics. In the case of cocci in chains appearing pink on a Gram stain, it suggests that the bacteria may have lost their ability to retain the crystal violet dye due to antibiotic-induced changes in cell wall structure.
A bronchial washing specimen for routine bacterial, fungal and acid-fast culture was received. The sample volume is insufficient to perform all the requested tests. Which of the following actions should be performed?
Explanation:
When faced with an insufficient sample volume for requested tests, it's prudent to communicate with the clinician to determine the most critical cultures based on the patient's clinical presentation and suspected diagnosis. This ensures that limited resources are directed toward the most relevant tests, optimizing patient care.
Which of the following reagents is used as the mordant and oxidant in the Weigert's hematoxylin?
Explanation:
In the Weigert's hematoxylin staining method, ferric chloride serves as the mordant and oxidant. It helps intensify the staining of nuclei with hematoxylin and promotes the formation of a complex that binds to cellular structures.
What reagent is applied prior to the counterstain in a gram stain procedure?
Explanation:
In a Gram stain procedure, the decolourizer is applied after the primary stain (crystal violet) and prior to the counterstain (safranin). Its purpose is to remove the primary stain from gram-negative bacteria while allowing the retention of the stain by gram-positive bacteria.
A dark brown pigment is noted on formalin-fixed, hematoxylin, and eosin-stained sections. What action can prevent this from occurring?
Explanation:
Maintaining formalin at a neutral pH helps prevent the formation of dark brown pigment on tissue sections during fixation. Acidic formalin can lead to excessive pigment formation, affecting the quality of staining and tissue interpretation. Therefore, ensuring the formalin solution remains at a neutral pH is essential for optimal tissue preservation and staining in histotechnology.
Which of the following actions should be taken when the hematoxylin and eosin stain lacks three distinct shades of pink?
Explanation:
In histotechnology, the quality of staining is crucial for accurate tissue examination. Checking the pH of eosin is important because an incorrect pH level can affect the staining process and result in inadequate differentiation of tissue components, such as lacking distinct shades of pink in the eosin stain. Adjusting the pH can help ensure proper staining and interpretation of tissue samples.
Where should a tissue specimen for the frozen section be sent?
Explanation:
Tissue specimens for frozen section analysis are typically sent to the histology department. Frozen section analysis involves the rapid processing of tissue specimens for immediate examination by a pathologist, often during surgery, to guide surgical decision-making. Histology technicians prepare frozen sections for examination using specialized techniques, making histology the appropriate department for handling such specimens.
Which of the following situations will cause mast cells to turn blue during metachromatic staining?
Explanation:
Mast cells turn blue during metachromatic staining when the pH of toluidine blue decreases. Metachromatic staining relies on the differential affinity of dyes for specific cellular components. Decreasing the pH of toluidine blue enhances its affinity for mast cell granules, causing them to turn blue.
Which of the following actions should be taken when tissue sections stained with hematoxylin and eosin show pale cytoplasmic staining?
Explanation:
Eosin is an acidic dye, and its pH affects the staining quality. If tissue sections show pale cytoplasmic staining, it indicates potential issues with eosin staining. Checking the pH of eosin and adjusting it with acetic acid if necessary can help restore optimal staining conditions, leading to improved cytoplasmic staining in histological specimens.
Which of the following staining problems results from the omission of 1% periodic acid solution in the Jones Methenamine silver technique?
Explanation:
The Jones Methenamine silver technique is used to visualize basement membranes in tissue sections. Omitting the 1% periodic acid solution in this technique prevents oxidation of the methenamine silver, resulting in a failure to stain the basement membrane.
Which of the following specimen orders prioritizes the processing of microbiology specimens correctly?
Explanation:
When prioritizing the processing of microbiology specimens, it is essential to consider factors such as urgency and specimen stability. CSF and blood cultures are typically considered urgent specimens due to their clinical significance, followed by urine and swabs in transport media. This order ensures the timely processing of critical specimens while maintaining the integrity of the samples.