Transcript DNA Fingerprinting Notes

Biotechnology engineering of organisms for
useful purposes
DNA Fingerprinting
Cloning
What is DNA
Fingerprinting?
 The chemical structure of everyone's DNA is
the same.
 The only difference between people (or any
animal) is the order of the base pairs.
 There are so many millions of base pairs in
each person's DNA that every person has a
unique and individual sequence.
What is DNA
Fingerprinting?
 Because there are so many millions of base pairs,
the task of identifying EVERY base pair would be
very time-consuming.
 Instead, scientists analyze small segments of DNA
where the base sequences tend to be the most
variable (~ 3 million bases) between individuals.
(About 13 locations not coding for genetic traits)
 The likelihood that any 2 people would share the
same DNA profile is 1 in a quintillion (18 0’s)
 Scientists are able to determine whether two DNA
samples are from the same person, related
people, or non-related people.
How is a DNA fingerprint
made?
 1) Restriction enzymes are added to the DNA sample
to cut it up into smaller pieces or fragments
How is a DNA fingerprint
made?
 2) Fragments are pulled through a gel
(by an electrical charge) and distribute
according to the size of the fragment
How is a DNA fingerprint
made?
 3) An x-ray picture is
taken of this
distribution and then
can be compared to
other DNA samples
How is a DNA Fingerprint
made?
 Different people
have different
restriction enzyme
“cut sites”
Person 1
Person 2
Resulting in different sized
DNA fragments.
Resulting in different band patterns
on a gel
What is DNA
Fingerprinting used for?
 Paternity/Maternity testing
 Criminal investigations (proving guilt & innocence!)
 Identification of 9/11 victims & other human remains
 about 20,000 pieces of human remains were
collected, a database of the victims’ DNA profiles
was created
 Super Bowl XXXIV Footballs
 Marked with invisible, yet permanent, strand of
synthetic DNA
 2000 Summer Olympic Souvenirs
 Human DNA (Australian athletes) added to ink used
to mark all official goods
What is DNA
Fingerprinting used for?
 Identify endangered and protected species as an
aid to wildlife officials (could be used for
prosecuting poachers)
 Detect bacteria and other organisms that may
pollute air, water, soil, and food
 Match organ donors with recipients in transplant
programs
 Determine pedigree for seed or livestock breeds
 Authenticate consumables such as caviar and
wine