Cytogenetic techniques and uses Flashcards
In cytogenetic testing there are 2 main types of testing, whole genome testing and targeted testing - name 3 techniques for each?
Whole genome testing 1) G banding 2) Next generation sequencing 3) Microarrays Targeted testing 1) FISH 2) MLPA 3) QF-PCR or qPCR
What is considered to be the conventional cytogenetic technique?
G banding
What are the 6 stages in the G banding process?
1) Cell culture
2) Mitotic arrest
3) Hypotonic solution
4) Fixation to slide
6) Trypsin (enzyme) and leishman’s stain
7) Banding, shows AT rich and CG rich sections
Name the 6 molecular cytogenetic techniques?
1) Fluorescent in situ hybridisation FISH
2) Multiplex ligation dependent probe amplification MLDPA
3) Micro-array comparative genomic hybridisation (Array CGH)
4) Next generation sequencing
5) Quantitative fluorescent PCR (QF-PCR)
6) qPCR
What is the process of FISH?
You have a specific region of interest, could be whole chromosome or just a specific bit
Buy a fluorescently labelled DNA probe
Denature both the target DNA on the slide and the probe
Allow time for hybridisation
Wash off any excess probe
Use a counter stain to stain any regions you’re not interested in a different colour
Visualisation using UV light
What are the 3 different types of probe used in FISH and give an example of a time when each would be used?
1) Unique sequence - highlight a small part of a chromosome or a specific gene
2) Centromeric - highlights the number of a particular chromosome present
3) Paint - paint each chromosome a specific colour
How might centromeric probes for FISH be used in a sex mismatched bone marrow transplant?
Look at the cells in the patient
See whether the bone marrow has taken the sex of the donor and whether patient cells have come back
Shows how successful the transplant have been in whether the host cells have started to come back (ie. not successful if they have)
