Microscopy techniques — MCQs

A medical technician is trying to isolate a pathogen from the sputum sample of a patient. The sample is heat fixed to a slide then covered with carbol fuchsin stain and heated again. After washing off the stain with clean water, the slide is covered with 1% sulfuric acid for decolorization. The sample is rinsed again and stained with methylene blue. Microscopic examination shows numerous red, branching filamentous organisms. Which of the following is the most likely isolated pathogen?

An investigator is examining tissue samples from various muscle tissue throughout the body. She notices that biopsies collected from a specific site have a high concentration of sarcoplasmic reticulum, mitochondria, and myoglobin; they also stain poorly for ATPase. Additionally, the cell surface membranes of the myocytes in the specimen lack voltage-gated calcium channels. These myocytes are found in the greatest concentration at which of the following sites?

An investigator is studying neuronal regeneration. For microscopic visualization of the neuron, an aniline stain is applied. After staining, only the soma and dendrites of the neurons are visualized, not the axon. Presence of which of the following cellular elements best explains this staining pattern?

An investigator studying targeted therapy in patients with gastrointestinal stromal tumors requires a reliable test to determine the spatial distribution of CD117-positive cells in biopsy specimens. Which of the following is the most appropriate test?

A group of scientists is studying the mechanism by which the human papillomavirus (HPV) vaccine confers immunity. They observe that during inoculation of test subjects, certain viral proteins are taken up by the organism's antigen-presenting cells (APCs) and presented on major histocompatibility complex (MHC) class I molecules. Which of the following is the correct term for the process that the scientists are observing in this inoculation?

A 12-year-old male presents to the emergency department following several days of facial edema. A urinalysis confirms proteinuria and hematuria. Once admitted, a kidney biopsy is viewed under an electron microscope to confirm the diagnosis of minimal change disease. In the following electron micrograph, what process occurs in the structure marked with an arrow?

A 36-year-old man undergoes surgical intervention due to a right upper quadrant stab wound. His gallbladder was found to be lacerated and is removed. It is sent for histological evaluation. The pathologist examines the slide shown in the exhibit and identifies several structures numbered the image. Which of the following statements is correct?

This type of epithelium is most commonly seen in which of the following organs?

Identify the type of papillae of the tongue shown in the histological image below:

An investigator is conducting a study to document the histological changes in the respiratory tree of a chronic smoker. He obtains multiple biopsy samples from the respiratory system of a previously healthy 28-year-old man. Histopathological examination of one sample shows simple cuboidal cells with a surrounding layer of smooth muscle. Chondrocytes and goblet cells are absent. This specimen was most likely obtained from which of the following parts of the respiratory system?