Mutation detection techniques Flashcards
Humans inherit a haploid set of how many chromosomes from each parent?
23 chromosomes each
Trait or group of traits resulting from transcription & translation
Phenotype
DNA nucleotide sequence responsible for a phenotype
Genotype
It is used to describe inherited or somatic sequence alterations
Variants
(True or False)
Balanced polymorphisms are maintained through a balance of positive & negative genotype
False
phenotype
Genome mutations result in cells that are _____
Aneuploid
Most abundant protein in the nucleus
Histones
2 nonhistone protein complexes
Condensin I
Condensin II
Expression of a gene when it is moved or inserted in a chromosomal position different from its original position
Position effect
They maintain mitotic chromosome structure
Nonhistone protein complexes
They are looped onto protein scaffolds to from 30 nm fibers
30 nm interphase fibers
Compacted into 1400 nm fibers and seen as karyotypes
Solenoid coils
The first classic indicator of apoptosis
Loss of organization of solenoid coils
Highly compacted DNA is less available for RNA transcription
Chromosome topology
(True or False)
When DNA is NOT compacted, it is harder to unwind and relax
False
Compacted DNA = harder to unwind
This is the site of attachment of chromosome to spindle apparatus
Centromere
Protein complex which serves as the centromere’s means of connection to the spindle apparatus
Kinetochore
These are highly repetitive sequences at the centromere’s nucleus
Alpha Satellite Sequences
(True or False)
Alpha Satellite Sequences interfere w/ chromosome compaction
True
Centromere is in the middle
Metacentric
Has a longer arm & shorter arm
Submetacentric
Centromere is near the end
Acrocentric
Centromere may not be seen anymore
Telocentric
2 fluorescent dyes used in Q banding
Quinacrine
Quinacrine mustard
Stain used in G banding
Giemsa stain
Mild treatment used in G banding
2x standard saline citrate
for 60 mins at 60C
It is seen when chromosomes are harshly treated
R banding
(True or False)
Acridine orange is used in C banding
False
R banding
Seen when chromosomes are treated with alkali
C banding
The component stained in C banding
Centromere
How many bands are stained per chromosome in High resolution banding
300-500
Stain used in Nuclear organizing region
Silver nitrate
(True or False)
Chromosomes treated with silver nitrate will stain at constricted regions on Telocentric regions
False
Acrocentric
DAPI is also knowns as
4’6-diamino-2-phenylindole
It is used to visualize chromosomes and whole nuclei
DAPI
Observation of metaphase chromosome structure by arranging them by size
Karyotyping
It stimulates cell division
Mitogen (phytohemaglgutinin)
Inhibitor of mitotic spindle formation
Colcemid
Loss of chromosome material
Deletion
Gain of chromosome material
Insertion
Excision, flipping, reconnecting chromosome material
Inversion
2 types of inversion
Pericentric
Paracentric
two short/long arms separate into daughter cells
Transverse split
Metacentric chromosome from a transverse split
Isochrome
Results from deletion of genetic regions from ends of chromosome
Ring chromosome
Translocated or rearranged parts from 2 or more unidentified chromosome joined
Derivative chromosome
It is the detection of protein, RNA, DNA structures placed in the cell or in situ
Fluorescence in situ hybridization
It is more rapid w/ higher resolution than karyotpying
FISH
It is used to study prenatal samples, tumors, hematologic malignancies
Interphase FISH
2 types of probes used in Interphase FISH
Centromeric probes (CEN) Telomeric probes
Probe that is useful for detection of chromosome structural abnormalities
Telomeric probes
Probe that hybridizes with the alpha satellite sequences of centromeres
Centromeric probes
Fading or loss of probe signal emission due to photochemical destruction
Photobleaching
Analysis of small regions not visible by regular chromosome banding
Metaphase FISH
It uses a special imaging software to distinguish all 23 chromosomes by specific colors
Spectral karyotpying
These 2 are used as a probe on a normal metaphase chromosome spread in Comparative genome hybridization
DNA
Reference samples
It is capable of identifying the location of deletions or amplifications
Comparative Genome Hybridization
This type of mutation doesn’t change the amino acid sequence
Silent mutations
The amino acid sequence in this type of mutation is changed but have similar biochemical properties
Conservative substitutions
The amino acid is replaced with biochemically different amino acid
Non-conservative substitutions
It terminates proteins prematurely due to a nucleotide substitution
Nonsense substitution
Nonsens substitution produces a ______
stop codon
It disrupts the reading frame due to insertion/deletion in nucleotide or RNA
Frameshift mutation
(True or False)
In frameshift mutation more than 3 nucleotides are changed
True
3 types of mutation that will generate different phenotypes
Nonconservative
Nonsense
Frameshift
5 Biochemical methods for detecting mutations
Enzyme immunoassays Immunohistochemistry High-performance Liquid Chromatography Gas Chromatography Mass Spectrometry
This method uses specific antibodies or other ligands to detect target molecules
Enzyme immunoassay
Tissues in this method are prepared thru fixing in formalin, snap freezing, cutting in cryostat
Immunohistochemistry
This is faster than indirect staining but has limited signal intensity
Direct Antibody staining
It uses fluors/enzymes not attached to the antibody that binds with the target molecule
Indirect Antibody test
2 phases oh High performance liquid chromatography
Mobile
Stationary
(True or False)
In Gas chromatography, the Mobile phase is a high boiling point liquid, and the Stationary phase is an inert gas
(False)
Mobile phase = inert gas
Stationary = high boiling point liquid
It is a test coupled with Gas chromatography so it can be used to detect biomarkers of disease
Mass spectrometry
This method converts molecules into ions that can be moved in a magnetic field based on their charge and mass
Mass spectrometry
2 types of Mass spectrometry
Electrospray ionization (ESI) Matrix-assisted laser desorption ionization (MALDI)
Single base pair resolution by hybridization
Array technology
Short double stranded products of PCR products are denatured followed by rapid cooling
Single-stranded confirmation polymorphism
Utilizes differences in the melting temperatures of your short sequences
Allele-specific oligomer hybridization
It includes a post amplification step of real time PCR
Melt-curve analysis
It detects point mutations and SNPs
Sequence-specific PCR
This enzyme recognizes the structure formed by hybridization of the normal/mutant pole
Cleavage enzyme
It follows the principle of heteroduplex analysis but uses a duplex RNA
Nonisotopic RNase cleavage assay
Useful for mutations that change the structure of restriction enzyme target site or changes the size of a fragment
Restriction fragment length polymorphisms (RFLPs)
(True or False)
Gene names are capitalized and set in italics with hyphens
False
without hyphens