Question 1

a) In the chemical fixation step of an H&E protocol describe why perfusion of a tissue is preferred over immersion.

b) You receive a freshly prepared slide of a liver tissue that a lab colleague prepared with an H&E protocol. Upon placing it under the microscope you notice that the integrity of the cells are perfectly conserved but that there is close to no contrast throughout the slide. Your colleague is 100% certain that he used the correct dyes and you trust his certainty on that matter. Considering the above information, what did your lab mate do wrong?

c) Provide a ONE sentence description of immunohistochemistry and provide a short (2 sentences max) explanation of the scientific concepts on which it is based.

Question 2

a. Describe the 5 key functions of the basement membrane and why diseases affecting its integrity are of a huge concern.

b. Describe the two constitutive elements of a proteoglycan. Describe how a proteoglycan differs from a glycoprotein. Provide a short description of the proteoglycan specific to the basement membrane and its function it participates.

c. In which layer of the epithelium are stem cells located? Provide the two biological principles (Time & Quantity) that govern the proliferation of these stem cells.

d. Provide an explanation as to why cells are treated with taxol (a microtubule stabilizing drug) do not complete mitosis and state the stage of mitosis in which these cells will remain.

Question 3

Medical histology can be used for various purposes, e.g. observing the state of a diseased organ, assessing the structure of an organ thought to be dysfunctional, searching for the manifestation of parasite contamination , etc.. Go to a scientific search engine (ex: PubMed) and find a research article published in the last three years that uses histology.

- Explain why the investigators used a histological technique in this publication (how was it useful, how will it answer the aim/question of the investigation, and why not use another technique)

- Describe the protocol used for this histological preparation (is it standard H&E, have other stains been used, was immunohistochesmitry used...)

- Add a figures of this publication which shows the histological results and discuss how this figure fits in the publication (in terms of the results it offers, and how it addresses the question the investigators were out to answer)

References: All websites, papers, and textbooks must be referenced in the text and in a bibliography at the end. *Note- Wikipedia and your professor's lecture notes are NOT appropriate references!