Histopathology

Question 1

What is the difference between histopathologists and cytopathologists

Answer 1

Histopathologists look at the architectural structure of tissues, where cytopathologists look at the morphology of cells

Question 2

What substances are needed for analysis of biopsies

Answer 2

Formalin is used to preserve tissues, paraffin is used to be able to cut tissue into thin slices, a stain to elucidate the details of interest

Question 3

Which instrument cuts the biopsies in thin slides

Answer 3

Microtome, a microscopically cutting device

Question 4

What is the Ziehl-Nielsen stain used for in histopathology

Answer 4

The Ziehl-Nielsen stain is used to stain acid-fast bacteria

Question 5

Which stain is used in histopathology to identify leukocytes in tissues

Answer 5

Haematoxylin and eosin stain that elucidates the nuclei and the cytoplasm in leukocytes

Question 6

What is resection specimen

Answer 6

A tissue that is removed during surgery and then used for diagnosis in histopathology, mainly for stage of cancer

Question 7

What instrument is used to make frozen specimens and when is this used

Answer 7

Cryostat, used by pathologist during real time surgery to look at tissues to give diagnosis that guides surgeon in his decisions

Question 8

How long does it take for frozen specimens, biopsies and resection specimens to get to clinician

Answer 8

Frozen specimens approximately 30 minutes, biopsies 2-3 days and resection specimens 5-7 days

Question 9

What are fine needle aspirates used for

Answer 9

To take cells for diagnosis at locations in the body that are hard to get access to without need for surgery

Question 10

Which substances are used in immunohistochemistry

Answer 10

Antibodies that bind to specific molecule of interest, either conjugated to enzyme or fluorophore so to stain place of binding

Question 11

What region of antibodies is conjugate attached to

Answer 11

Fc-region of antibody

Question 12

Which types of conjugations can be attached to antibodies

Answer 12

Enzymes, magnetic beads, fluorophores/fluorescent probes and drugs

Question 13

Which kind of conjugation does the CD31 cancer immunohistochemistry staining use

Answer 13

Enzymatic conjugation to antibody

Question 14

What is the advantage of fluorescent probes

Answer 14

This form of staining allows very rapid measurement of molecules on cells because colouring is already there

Question 15

What is multiplexing and why is it used

Answer 15

Attaching multiple different antibodies with different fluorescent probes to different molecules on cells, because some clinical samples are very precious and small volume

Question 16

What is magnetic bead conjugation used for

Answer 16

To purify one cell type from tissue by attaching antibody to specific cell marker

Question 17

What cytotoxic drug is added to Kadcyla drug for breast cancer and what receptor does it bind to

Answer 17

The chemical cytotoxic drug emtansine is bound to anti-HER2-antibody that specifically binds to the HER2-receptor on breast cancer cells

Question 18

What is the difference between direct and indirect detection in antibody diagnostics

Answer 18

In direct detection, one antibody type is used to detect certain molecules in sample. In indirect detection, a secondary antibody is used that binds to the primary antibody and this secondary antibody can be detected.

Question 19

What are antibody diagnostics used for in blood transfusions

Answer 19

Antibody diagnostics are used in blood transfusion to find out blood group of recipient and present antibodies in blood plasma and so linking it to the right type blood transfusion

Question 20

What is an immunoassay

Answer 20

Detection of substances in the blood plasma by antibodies such as detection of hormones or specific antibodies

Question 21

In what diseases might immunodiagnosis be useful (three examples)

Answer 21

In infectious diseases where body has created antibodies that can be detected and indicate infection, in myelomas where antibodies are formed and in allergies where there is more circulating IgE than normal

Question 22

What does ELISA stand for and what does it detect

Answer 22

Enzyme-linked immunosorbent assay, it can detect molecules that are adhered to sample surface, typically plasma molecules

Question 23

How does it detect different concentrations of antigens and what is used as reference

Answer 23

The antibodies are conjugated to enzymes that turn colourless substrate into coloured product and this absorbance is measured and compared against standard curve to allow for quantitive analysis

Question 24

What is flow cytometry and how does the procedure work

Answer 24

Flow cytometry is a detection method to detect specific cell types that are bound to marker antibodies with fluorescent probes that are then moved in a single past a laser and every probe reflects light differently and this used to gain information on cell type, volume and granulation

Question 25

Which cells are often analysed by flow cytometry

Answer 25

Lymphocytes

Question 26

What different information can be determined about cells in flow cytometer

Answer 26

Different cell type, the size of the cell and the granularity of the cell

Question 27

Which antibodies are used for detecting T-cells (cytotoxic and helper), B-cells and NK cells

Answer 27

Anti-CD3 for all T cells, anti-CD4 for Th-cells, anti-CD8 for Tc-cells, anti-CD19 for B cells, anti-CD56 for NK cells

Question 28

How are cells moved through flow cytometer

Answer 28

They move from sample past laser beams in a single stream of cells

Question 29

What does the oil red O stain elucidate

Answer 29

Stains lipids in tissues

Question 30

What does Congo red stain elucidate

Answer 30

ECM components such as elastin and collagen