[W9] Histopathology Flashcards
(15 cards)
What does immunohistochemistry detect?
Antigens in tissue using labelled antibodies.
Immunohistochemistry is a technique used to visualize the presence and location of proteins in tissue sections.
What is the difference between polyclonal and monoclonal antibodies?
Polyclonal = multiple epitopes (↑ sensitivity), Monoclonal = one epitope (↑ specificity)
Polyclonal antibodies are produced by different B cell lines, while monoclonal antibodies are produced by identical immune cells.
What is PIER and HIER?
PIER = enzymatic retrieval; HIER = heat-induced antigen retrieval.
These methods are used to unmask antigens in tissue for better antibody binding.
Which enzymes are used in IHC detection?
Horseradish peroxidase (HRP) and alkaline phosphatase (AP)
These enzymes catalyze reactions that produce a detectable signal in immunohistochemistry.
What is the ABC method in IHC?
Avidin-biotin complex amplifies signal using enzyme-linked biotin.
This method enhances the detection sensitivity of antigens in tissue samples.
What does H&E stain?
Haematoxylin stains nuclei blue, eosin stains cytoplasm pink.
H&E staining is a common technique used in histology to visualize tissue structure.
What are trichrome stains used for?
To visualise connective tissue, collagen, and muscle.
Trichrome staining helps differentiate between various tissue components based on their staining properties.
What does the Human Tissue Act 2004 regulate?
Use, storage, and disposal of human tissue with proper consent.
This act ensures ethical practices in handling human tissues in medical and research settings.
What’s the difference between histology and cytology?
Histology = tissues, Cytology = individual cells.
Histology focuses on the study of tissue architecture, while cytology examines cellular morphology.
What is the purpose of embedding in histology?
To support tissue for sectioning by using molten wax.
Embedding allows for the creation of thin sections for microscopic examination.
What does OSNA detect in lymph nodes?
CK19 mRNA to identify cancer spread.
OSNA is a molecular technique that provides rapid assessment of lymph node metastasis.
What is the copy number threshold for macrometastasis in OSNA?
> 5000 copies/µL
This threshold indicates a significant level of cancer spread in the lymph nodes.
What is one key clinical benefit of OSNA?
Enables intraoperative decision-making for lymph node clearance.
OSNA allows surgeons to make real-time decisions during surgery based on lymph node status.
Which cancers may OSNA be applied to?
Breast, colon, gastric, lung, endometrial
OSNA is used for various cancer types to assess lymph node involvement.
What does OSNA improve in cancer treatment?
Staging accuracy, prognosis, and reduces reoperation.
By providing precise information on lymph node involvement, OSNA enhances treatment planning.
