Molecular Diagnostics in Cancer 1 Flashcards
(23 cards)
What is the focus of Molecular Diagnostics in Cancer?
Techniques for analysing genetic changes in cancer.
What are the uses of Molecular Diagnostics in Cancer?
Used for diagnosis, monitoring, and guiding treatment.
What are biomarkers?
Substances increased in cancer (from cancer cells or surrounding tissues).
Where can biomarkers be found?
In blood, urine, stool, and biopsies.
What are the uses of biomarkers?
Diagnose disease, track response to treatment, predict prognosis.
What is the core principle of Hybridization?
Complementary nucleic acid strands bind (DNA↔DNA, DNA↔RNA).
What is the application of Hybridization?
Used in probes (to detect sequences) and primers (to amplify DNA in PCR).
What does Fluorescence In Situ Hybridization (FISH) detect?
Gene/chromosomal abnormalities using fluorescent probes.
What abnormalities can FISH detect?
Deletions, duplications, translocations, inversions, and aneuploidy.
What is an example of FISH detection in breast cancer?
HER2 amplification (25–30% of breast cancers): worse prognosis, can be treated with anti-HER2 drugs.
What is CISH?
Chromogenic In Situ Hybridization, combines FISH + IHC.
What does CISH visualize?
Hybridized probes with enzymatic colour change.
What is PCR?
Polymerase Chain Reaction, amplifies specific DNA sequences millions of times.
What are the requirements for PCR?
Template DNA, forward/reverse primers, DNA polymerase (e.g. Taq or Pfu), dNTPs.
What are the steps of PCR?
- Denaturation (94°C) 2. Primer Annealing (30–65°C) 3. Extension/Synthesis (72°C).
How many cycles are repeated in PCR?
25–40 cycles for exponential amplification.
What is RT-PCR?
Reverse Transcriptase PCR, converts RNA → cDNA → then amplifies by PCR.
What is the purpose of RT-PCR?
Used for studying gene expression (mRNA).
What is Slab Gel Electrophoresis?
DNA bands stained (e.g. ethidium bromide), visualised under UV.
What is Capillary Gel Electrophoresis?
DNA fragments separated in thin tubes, higher resolution; useful for multiplex detection with fluorescent primers.
What is Real-Time PCR (qPCR)?
Monitors amplification in real-time and measures how much DNA/RNA was present initially.
What are the probes used in qPCR?
TaqMan®: Fluorescent signal released when DNA pol degrades probe. SYBR® Green: Binds double-stranded DNA, fluoresces upon binding.
What is an application of Real-Time PCR?
Used to measure circulating tumour cells in cancer patients and in RT-qPCR to quantify gene expression.
