Karyotyping (PPT proper) Flashcards
Karyotyping methods is ___ (classical/molecular) cytogenetics
Classical
The number and appearance of chromosome in the nucleus of a eukaryotic cell
Karyotype
Information found on the karyotype (4)
Size of chromosome
Position of centromere
Presence of secondary constrictions
Size of satellites
Karyotype comes from the Greek word “___”, which means ___
Karyon
Nucleus
The study of the whole sets of chromosomes
Karyology
The standard format of representing chromosomes as diagram when the haploid set of chromosomes of an organism are ordered in a series of decreasing size
Idiogram or karyogram
Show larger differences between smaller and larger chromosome in a set
Asymmetric karyotype
Have more acrocentric chromosomes and relatively advance feature
Asymmetric karyotype
Show lesser difference between smaller and larger chromosome in a set
Symmetric karyotype
Have more metacentric chromosomes and no advanced feature
Symmetric karyotype
In 1931, __ ____, a Russian scientist suggested that in flowering plants there is a predominant trend towards karyotype asymmtery
GA Levitzky
Proportion of metacentric, acrocentric chromosomes in a set
Degree of asymmetry
Ratio between size of largest and smallest chromosomes in a set
Degree of asymmetry
The reagent that induces mitotic activity
Phytohemagglutin (PHA)
Arrests the cell cycle at metaphase stage
Colcemic (colchicine)
A part of a chromosome which is clearly distinguishable from its adjacent segments by appearing darker or lighter
Band
A process where DNA and histones causes nucleosomes to pack tightly together
Methylation
A process which results in loose packing of nucleosomes
Histone acetylation
5 major steps in karyotypimg
- Short term lymphocyte culture
- Harvesting of lymphocyte
- Fixing the cells
- Making the chromosome slides
- Slide analysis
In the short term lymphocyte culture, the cells must be in ___ phase because splitting of a cell line __ days before harvesting, and changing the medium __ day before harvesting, stimulates cell ___ significantly
Logarithmic
2
1
Proliferation
In the harvesting of lymphocytes, addition of pre-warmed ___ (also known as ___), is done into the culture which is incubated for ___ mins
Colcemid
Colchicine
15
In the harvesting of lymphocytes, optimal exposure time to colcemid requires a balance between ____ ____ ___ of cells and ___ of colcemid
proliferative activity index
concentration
In the harvesting of lymphocyte, the tube must be centrifuged at ___ RPM for __ mins and the cell pellet should be resuspended in warm ___ solution (can be ___ or ___ ___) and should be incubated at ___ (temperature) for ___ mins
Hypotonic
KCl
Sodium citrate
room temp
15
In the harvesting of lymphocytes, additional modifications that allow enrichment of long (prometaphase) chromosomes is by using ___ __ or ___ ___ (added before harvesting), or ___ (__), added before colcemid treatment
Actonimycin D
Ethidium bromide
Bromodeoxyuridine
BrdU
In fixing the cells, the cell suspension in ___ state will be centrifuged for ___ RPM for __ mins
Hypotonic
1200
5
In fixing the cells, the cell pellet should be treated with fixative solution. What is the component for this solution? Otherwise called as?
Absolute methanol : Glacial Acetic acid in 3:1 ratio
Carnoy’s fixative
The process of fixing the cells will be repeated for how many times? What is the temperature of incubation and for how many minutes?
3 times
4 degrees Celsius
10
In making the chromosome slides, how many cold slides should be layered next to each other in a paper towel?
5-6
In making the chromosome slide, how many drops of the sample should be dropped onto each slide?
2-3
In making the chromosome slide, what banding will be stained?
GTG-banding
In slide analysis, the slides that will be chosen for analysis and visualization must be:
- Properly ___ chromosomes
- Clearly defined ___ spreading
Trypsinized
Metaphase
Banding technique in 1958 by Caperson et al.
Quinacrine
Banding technique in 1971 by Summer et al.
Giemsa
Banding technique in 1973 by Matsui & Sasaki
NOR
Banding technique in 1978 by Linde & Laurse
Centromeric
Identify the banding type:
Giemsa stain
AT-rich regions stain darker than GC-rich regions
G-Banding
Identify the banding type:
Quinacrine fluorescent dye stains AT-rich regions
Q-banding
Identify the banding type:
Banding pattern is opposite G-banding
R-banding
Identify the banding type:
Stains heterochromatic regions close to the centromere
C-banding
Identify the banding type:
Usually stains the entire long arm of the Y chromosome
C-banding
Identify the banding type:
Simple and Versatile
Used where G band is not accepted
Used in study of chromosome heteromorphism
Q-banding
Identify the banding type:
Has a tendency to fade during examination
Photo-degradation
Q-banding
Identify the banding type:
Chromopore absorb light of a particular wavelength due to a chemical bond formed between dye and light
Q-banding
Identify the banding type:
UV light breaks the chemical bond
Q-banding
Identify the banding type:
Used in identification of bands rich in Sulfur content
G-banding
Identify the banding type:
Used in the identification of chromosomal abnormalities and in Gene mapping
G-banding
Identify the banding type:
Not used in plants
G-banding
Identify the banding type:
Used in the identification of nucleolar organize region
N-banding
Identify the banding type:
Superior banding pattern for plants
N-banding
Identify the banding type:
Identification of chromosomes particularly in insects and plants
C-banding
Identify the banding type:
Identification of bivalents at diakineses using both centromere position
C-banding
Identify the banding type:
For paternity testing and gene mapping
C-banding
In ISHCN, the lowest number is given to the one ___ (proximal/distal) to the centromere, while the highest number is at the ___ (proximal/distal) to centromere
Proximal
Distal
