Histochemical Stains in Histology

Which of the following staining techniques is best suited for identifying fungi in tissue samples?

A pathologist suspects a carbol-fuchsin stain is producing false negatives. Which step is MOST likely to have been performed incorrectly?

Which of the following stains is used to identify glycogen and mucosubstances in tissue sections?

Which stain is MOST appropriate for visualizing elastic fibers in blood vessels?

After performing a silver stain, the control tissue shows over-impregnation with silver. What adjustment should be made to correct this issue?

Which staining method relies on the principle of polarized light to visualize specific tissue components?

Which of the following enzyme histochemistry techniques can be used to identify sites of high metabolic activity within muscle fibers?

A bone marrow biopsy is tested with Prussian blue. What is the MOST likely target of this stain?

In immunohistochemistry, what is the purpose of antigen retrieval?

Which of the following Romanowsky stains is commonly used for routine staining of peripheral blood smears?

A pathologist observes a weakly stained Periodic acid-Schiff (PAS) reaction in a tissue sample known to contain high levels of glycogen. Which of the following steps might be modified to enhance the PAS reaction?

When performing a Gram stain on a sample, the safranin step was omitted. What would be the likely appearance of Gram-negative bacteria?

A bone marrow trephine biopsy is stained with Giemsa stain. What cellular components are MOST readily identifiable with this stain?

In a research setting, a scientist needs to differentiate between various types of connective tissue fibers in a skin biopsy. Which of the following stains would be MOST suitable for this purpose?

During an enzyme histochemistry procedure for succinic dehydrogenase, the tissue section shows no enzyme activity despite appropriate controls. What is the MOST probable cause?

A laboratory is validating a new immunohistochemical stain for cytokeratin. The positive control tissue shows strong staining, but the negative control also exhibits some staining. What is the FIRST step to optimize the staining?

A pathologist wants to visualize calcium deposits in a decalcified bone sample. Which staining method is MOST appropriate?

Which of the following stains is MOST appropriate for identifying Pneumocystis jirovecii in lung tissue?

After performing a silver stain, the background is excessively dark, obscuring the target structures. Which modification to the staining protocol would MOST likely correct this issue?

In immunohistochemistry, a high background staining is observed even after optimizing antibody concentrations and blocking steps. Which additional control can BEST help differentiate between specific and non-specific staining?

A tissue sample stained with Alcian blue shows a lack of staining in areas known to contain acidic mucosubstances. Which of the following is the MOST likely cause of this staining failure?

In a Gram stain procedure, the mordant is applied to:

Which of the following BEST describes the function of silver ions in the Grocott methenamine-silver (GMS) stain for fungi?

A pathologist is examining a liver biopsy and wants to differentiate between collagen and muscle fibers. Which of the following stains would be MOST appropriate?

During an enzyme histochemistry procedure for acid phosphatase, the tissue sections are incubated at an elevated temperature. What is the MOST likely effect of this change on the staining?

In immunohistochemistry, what is the purpose of a blocking step prior to the application of the primary antibody?

Which of the following is the MOST appropriate fixative for preserving lipids for subsequent staining with Oil Red O?

A Wright-Giemsa stained bone marrow aspirate reveals an increased number of cells with granules that stain intensely red-orange. Which cell type is MOST likely increased?

Which of the following is the PRINCIPLE behind von Kossa staining for calcium?

The purpose of Melanin Bleach is to: