Cytogenetics Methods Flashcards
reagent that inhibits formation of spindle fibers
colchicine
What stage are cells arrested at for karyotyping?
metaphase
banding technique used for plant cells
N-banding
reagent that acts as mitogen
phytohemagglutinin (PHA)
banding technique used for animal cells
G-banding
Why is trypsin used in karyotyping animal cells?
Trypsin denatures proteins (histones)
type of staining that produces uniformly-stained chromosomes
solid staining
information obtained from solid staining
number, size, shape, and arm ratios of individual chromosomes
Who invented Romanowsky staining?
Dmitri Romanowsky (1891)
type of staining that produces chromosomes with domains, patterns, or bands
differential staining
stain used in Q-banding
quinacrine mustard
this absorbs light of a particular wavelength due to a chemical bond formed between dye and light
chromophore
Which region stains darkly in Q-banding?
AT-rich regions
What stain is used in G-banding?
Giemsa stain
How does Giemsa bind to DNA?
intercalation
Giemsa is a mix of ____ and ____ dyes.
thiazine and eosin
The interaction of DNA with thiazine and eosin components results in the brightening of _____-rich regions.
sulphur
What treatment is used for N-banding?
5% trichloroacetic acid + 0.1N HCl
What is stained in N-banding?
structural non-histone proteins linked to NOR (nucleolar organizing region)
What stain is used in C-banding?
Giemsa stain
What type of heterochromatin is found in the centromere?
constitutive heterochromatin
What banding technique/s reveal facultative heterochromatin?
G- or Q-banding
What banding technique/s reveal euchromatin?
R-banding
What banding technique/s reveal constitutive heterochromatin?
C-banding
organic molecules capable of undergoing fluorescence
fluorochromes
This method makes use of specific DNA probes bound to fluorescent dyes
Fluorescence In Situ Hybridization (FISH)
sequence that corresponds to sequence of the gene in a particular segment
probe
What are the steps of FISH?
- labeling of probe with fluorescent dye
- denaturation and hybridization
What are the three types of probes?
- whole chromosome painting probes
- locus-specific probes
- centromeric (satellite) probes
