RFLP Flashcards
(17 cards)
A DNA fingerprint (or DNA profile) is a pattern of bands made up of
specific fragments from an individual’s DNA.
Banding patterns from two individuals can be compared to determine if
they are related
two species can be compared to determine if they are related true or false
true
This technology can be used in
forensic science and in medical research.
Ex: Convicting criminals from bloodstains.
Determining the origin of diseases.
making a DNA fingerprint
The method for producing a DNA fingerprint is called Restriction Fragment Length Polymorphism (RFLP) analysis.
step 1:
The DNA sample is first cut into many fragments by a restriction enzyme.
step 2
the DNA fragments are then separated according to their size by gel electrophoresis.
gel electrophoresis
All DNA fragments are loaded at the top of the gel.
once electricity is run through the gel,
the smaller DNA fragments will travel farther than larger DNA fragments.
step 3
Radioactive probes are added and bind to DNA fragments to help them become visible.
step 4
Photographic film is applied to take a picture of DNA fragments.
step 5
photographic film is developed
Every person, except identical twins, has a
unique sequence of DNA in their cells.
In the non-coding sections of our DNA, there are
repeated patterns of meaningless code (e.g. ATCG-ATCG-ATCG).
The number of repeats between genes are different for each person….
Therefore, the fragment lengths will be different for each person.
Less than 1/1,000,000 chance that
two people have the exact same repeating pattern in five non-coding sections of DNA.
FBI compares 12 sections of DNA. The probability of two people having the same repeating pattern at 12 sites is
1/60,000,000,000.
