DNA FINGERPRINTING Flashcards
Conditions for DNA polymorphism:
- At least 2 variants
- Each variant is found in ≥1% of the
populatio
Multiple forms or changes in your DNA
DNA POLYMORPHISMS
under DNA POLYMORPHISMS, How do they happen?
● Occur due to mutations that occur in germ cells
● More common in non-coding regions
repetition of sequences several tens, hundreds, or thousands of times
TANDEM REPEATS
what is (VNTR)
Variable Number Tandem Repeats
Variable Number Tandem Repeats (VNTR) also called
“Minisatellite DNA”
Short Tandem Repeats (STR) also called
“Microsatellite DNA”
Unit size = 1-7 bp
VNTR or STR
STR
Repeats = 10-1,500
VNTR or STR
VNTR
*clustered near the telomeres
VNTR or STR
VNTR
DNA FINGERPRINTING
● Also called
DNA typing/profiling
99% of DNA sequences in the human genome are not identical
T OR F
F
DNA TESTING WHAT YEAR
Variations in serum proteins and RBC enzymes and the HLA system
1950s
DNA TESTING WHAT YEAR
Sir Alec Jeffreys from the Leicester
University (UK) pioneered DNA-based identity testing
1980s
DNA TESTING WHAT YEAR
Use of ABO blood group system for
identity testing, Not very extensive
1900s
DNA TESTING WHAT YEAR
Published first article on DNA
fingerprinting and saw its use in forensic science and paternity identification
1985
Method to be used depends on the nature of the sample and availability of reagents
DNA EXTRACTION
DNA EXTRACTION
Method to be used depends on the nature of the sample and availability of reagents
● Organic, Inorganic, or Solid-phase
○ Organic Phase reagent: _____
phenol-chloroform
Makes use of STRs (Short Tandem Repeat) that vary in length in different people
PCR AMPLIFICATION
PCR AMPLIFICATION
Length varies but the sequences flanking the ___ and ___ ends of the STR (Short Tandem Repeat), remain the same in all individuals
5’ and 3’
RESOLUTION OF FRAGMENTS
First method involved visualization using the _____________
carcinogenic EtBr stain
- carcinogenic EtBr stain
_____ is applied to the membrane to detect specific loci
Probe
first DNA fingerprinting method that was legally used in the court
PATERNITY TESTING
It is also one of the early uses of DNA fingerprinting as they found old bones in the Leicestershire, England which they believed to be from the late king.
GENEALOGY AND ARCHAEOLOGY
In the USA, they have the ___________, which allowed the crime labs in the entire country to share information about the DNA profiles of people.
DNA Identification Act of 1994
