Banding

Question 1

G Banding
uses _____ dye
Regions of chromosomes rich in ____ produce dark bands

Answer 1

Giemsa

A&T

Question 2

Q- banding
____ intercalating agent
Requires ____ microscope

___ fluorescence at pH ___

AT ____ fluorescence
GC _____ fluorescence

Distinguish

Answer 2

Quinacrine

fluorescence

Green-yellow

4.5

increase

inhibit

Distinguish:
Euchromatin contains active genes

Heterochromatin, AT rich, fluoresces more contains inactive genes

Question 3

Euch vs hetero

Answer 3

Euchromatin is prevalent in transcriptionally active cells

Heterochromatin is abundant in cells with less activity or no transcriptional activity at all

Heterochromatin stains dark; seen as scattered spots in the nucleus and grouped close to nuclear envelope

Question 4

R-banding involves —— stain

Generates:

Chromosomes are treated with ?

Detects ——when combined with G-banding

Answer 4

slid 7

R-banding involves Giemsa stain
Generates the reverse pattern from G-banding
Chromosomes are heated first

Detects deletions when combined with G-banding

Heat melts DNA helix in the AT-rich regions
Remaining GC-rich regions do not bind the stain as well.
It provides clarification about gene regions in the telomeres neighborhood

Question 5

C-banding
requires
——staining + —–treatment

Used for banding of ——– ——& identification of
1-
2-
3-

Answer 5

Giemsa staining + mild alkali treatment 
Used for banding of constitutive heterochromatin & identification of
1-Centromere 
2-Satellite DNA
3-Repetitive DNA sequences:
Located adjacent to centromeres 
Distal portion of the Y chromosome
Most significant bands on chromosomes 1,9,16 and Y

Question 6

NOR staining
Utilizes ____stain

stain mechanism and what does it identifies

Answer 6

Utilizes silver stain
Ag-stain accumulate in the nucleolus organizing regions
Satellite region of acrocentric chromosomes
Chromosomes 13, 14, 15, 21 and 22