Final - Cytogenetics Flashcards
1
Q
Clinical role of cytogenetics
A
- cytogenetics identifies chromosomal anomalies that may be associated with disease which contributed to the diagnosis and treatment of patients
- two categories of abnormalities = numerical and structural
2
Q
Clinical specimens used in cytogenetics
A
- blood
- bone marrow
- tissue
- amniotic fluid
- chorionic villi
3
Q
Specimen Preparations for Karyotyping
A
- Obtain sterile sample, transport biopsies on ice
- Alliquot into medium
- CO2 incubation
- Use of mitogen to encourage cell division and mitotic inhibitor to collect cells at metaphase
- Harvest via hypotonic solution to lyse cells
- Fix cells on slide
4
Q
Histone
A
- an alkaline protein that package and order DNA into structural units = nucleosomes
5
Q
Non-histone protein
A
- protein that remains after histones have been removed
ex: scaffold protein
6
Q
Centromere
A
- a region of a chromosome to which spindle fibers attach during cell division.
- the location of a centromes gives a chromosome its characteristic shape.
- p = short arm, q= long arm
7
Q
telomere
A
- short repeated DNA sequences located at each end of chromosomes
8
Q
nucleosome
A
- a bead-like structure composed of histone proteins wrapped with DNA
9
Q
metacentric
A
- centromere positioned in the middle of chromosome (centrally placed)
10
Q
submetacentric
A
- describes a chromosome whose centromere is placed closer to one end than the other
11
Q
acrocentric
A
- centromere placed very close to, but not at, one end
12
Q
telocentric
A
- centromere located at the terminal end of the chromosome
13
Q
3 criteria to classify and identify chromosomes
A
- Size
- Position of centromere
- Banding pattern
14
Q
G-banding
A
- darkly stained G bands
- metaphase spreads are treated with trypsin and stained with Giemsa stain
- observed with light microscope
15
Q
Q- banding
A
- bright flourescent bands under UV light same as darkly stained G bands
- uses chemical quinacrine mustard
