SNP intro ppts Flashcards
What is the difference between a mutation, an allele, and a DNA polymorphism?
-A mutation is defined as any change in a DNA sequence away from normal. This implies there is a normal allele that is prevalent in the population and that the mutation changes this to a rare and abnormal variant. In contrast, a polymorphism is a DNA sequence variation that is common in the population.
What is the approximate frequency of DNA polymorphisms in the human genome?
They occur almost once in every 1,000 nucleotides on average, which means there are roughly 4 to 5 million SNPs in a person’s genome.
Why are the majority of DNA polymorphisms found in noncoding regions of the genome?
The gene expression, gene splicing and transcriptional regulation activities are governed by the non-coding DNA. Therefore, SNP in the noncoding regions is more pathogenic than the coding region
Why are SNPs of special interest to medical research?
Researchers have found SNPs that may help predict an individual’s response to certain drugs, susceptibility to environmental factors such as toxins, and risk of developing particular diseases. SNPs can also be used to track the inheritance of disease genes within families.
Describe how SNPs can be detected by using DNA array
-The DNA microarray refers to a gene chip with a large number of probe DNA sequences in a specific arrangement immobilized on a solid substrate. The principle is the nucleic acid hybridization theory, and the detected sample DNA is hybridized with the DNA microarray and extended. Subsequently, the fragments of the non-complementary binding reaction on the chip are washed away, and the gene chip is subjected to laser confocal scanning. Fluorescence signal intensities are then measured and interpreted as the abundance of different genes through certain data processing
Describe concept of a probe used to detect as SNP?
-SNP microarray uses known nucleotide sequences as probes to hybridize with the tested DNA sequences, allowing qualitative and quantitative SNP analysis through signal detection. Compared with the traditional single cell diagnostic method, SNP microarray is a high throughput method, which is capable of performing thousands of reactions on the surface of the oligonucleotide chip at one time.
What kind of technology can detect SNP genotypes/haplotypes?
DNA chip with millions of DNA sequences on it
what is the probe of the DNA chip?
each probe cell contains copies of a specific probe complimentary to genetic information of interest.
the probe is single stranded, fluorescently labeled oligonucleotide
what is a probe pair?
probe cells are associated by pairs
How do polymorphisms limit PCR use for determining disease?
PCR is used to identify a very specific DNA segment, so polymorphisms could cause problems because they change part of a very specific sequence. PCR could amplify a gene that contained a variation
what does it mean to be low side?
idk
what does each probe cell contain?
each probe cell contains copies of a specific probe complimentary to genetic information of interest.
what is the target?
the free nucleic acid sample who’s identity is being detected, the nucleic acid that is washed over the chip
how many asos and controls can be gridded per CM2?
over 1 million different Asos and controls
what does the hybridized probe cell consist of?
labeled cDNA target and the oligonucleotide probe
