Lecture 2 Flashcards
Name the 4 types of biological samples used for genetic testing:
Peripheral blood, saliva, chorionic villi, and tissues (such as teeth and bone)
What type of DNA is taken from peripheral blood?
Germ line DNA
What type of tube is peripheral blood collected in?
EDTA → contains anticoagulants
What are the 3 different sections of a clinical DNA analysis lab?
Pre-pcr area (where the DNA is managed before amplification), pcr area ( where the DNA is amplified),and the post-pcr area (where amplified DNA is managed)
What is the term for amplified DNA?
Amplicon
What is the most notable method of first generation sequencing?
Sanger sequence
What is Sanger sequencing based on?
PCR amplification followed by direct sequencing of the amplicons
what is the amplification of all the regions of interest at a time in the same run?
Library
What are the 2 most common types of 2nd generation sequencing?
Illumina and ion torrent
What is 3rd generation sequencing also known as?
Single molecule sequencing
What is different about 3rd generation seq. compared to first and second?
There is no amplification performed before sequencing
Which method does 3rd generation sequencing follow?
2nd generation
What is 4th generation sequencing?
Single cell sequencing
What is an intrinsic bias related to pcr amplification?
It is possible to amplify regions characterized by insertions or deletions and can lead to incorrect or missing amplifications → allele dropout
What type of approach does the Sanger sequence use?
Qualitative
What are the 3 steps of Sanger sequencing?
Pcr amplification, direct sequencing of the amplicons, and analysis of the chromatogram
Direct Sanger sequencing currently done in labs used nucleotides that are modified how?
Labelled with different fluorescent dyes that allow the nucleotides to be distinguished by Color
The different colors produced b Sanger sequencing are organized into a what?
Chromatogram with peaks of different heights
Is Sanger sequencing quantitative or qualitative?
Qualitative
Why is Sanger sequencing the gold standard?
Very high accuracy
How is NGS defined?
Massive parallel sequencing
What is the main feature of NGS?
Preparation of the library
What determines the accuracy of NGS?
The qualify of the coverage
What was the 1st NGS platform used?
Roche 454
What is Roche 454 based on?
The pyrosequencing approach
What is the most important step in genetic counseling?
Informed consent
