Biotechnology Biotechnology - - engineering of organisms for useful purposes

DNA FingerprintingDNA Fingerprinting

CloningCloning

What is DNA What is DNA Fingerprinting?Fingerprinting?

The chemical structure of everyone's DNA is The chemical structure of everyone's DNA is the the samesame. .

The only difference between people (or any The only difference between people (or any animal) is the animal) is the order of the base pairs. order of the base pairs.

There are so many millions of base pairs in There are so many millions of base pairs in each person's DNA that every person has a each person's DNA that every person has a unique and individualunique and individual sequence. sequence.

What is DNA What is DNA Fingerprinting?Fingerprinting?

Because there are so many millions of base pairs, Because there are so many millions of base pairs, the task of identifying the task of identifying EVERYEVERY base pair would be base pair would be very time-consuming.very time-consuming.

Instead, scientists analyze small segments of DNA Instead, scientists analyze small segments of DNA where the base sequences tend to be the where the base sequences tend to be the most most variablevariable (~ 3 million bases) (~ 3 million bases) between individuals. between individuals. (About 13 locations not coding for genetic traits)(About 13 locations not coding for genetic traits)

The likelihood that any 2 people would share the The likelihood that any 2 people would share the same DNA profile is 1 in a quintillion (18 0’s)same DNA profile is 1 in a quintillion (18 0’s)

Scientists are able to determine whether two DNA Scientists are able to determine whether two DNA samples are from the samples are from the same personsame person, , relatedrelated people, or people, or non-relatednon-related people. people.

How is a DNA fingerprint How is a DNA fingerprint made?made?

1) Restriction enzymes are added to the DNA sample 1) Restriction enzymes are added to the DNA sample to cut it up into to cut it up into smaller pieces or fragmentssmaller pieces or fragments

How is a DNA fingerprint How is a DNA fingerprint made?made?

2) Fragments are pulled through a 2) Fragments are pulled through a gelgel (by an electrical charge) and distribute (by an electrical charge) and distribute according to according to the size of the fragmentthe size of the fragment

How is a DNA fingerprint How is a DNA fingerprint made?made? 3) An 3) An x-ray picturex-ray picture is is

taken of this taken of this distribution and then distribution and then can be compared to can be compared to other DNA samplesother DNA samples

How is a DNA Fingerprint How is a DNA Fingerprint made?made?

Different people Different people have different have different restriction enzyme restriction enzyme “cut sites”“cut sites”

Resulting in different band patterns on a gel

Resulting in different sized DNA fragments.

Person 1 Person 2

What is DNA What is DNA Fingerprinting used for?Fingerprinting used for?

Paternity/MaternityPaternity/Maternity testing testing Criminal investigations (proving Criminal investigations (proving guilt & innocenceguilt & innocence!)!) Identification of Identification of 9/11 victims 9/11 victims & other& other human human remains remains

about 20,000 pieces of human remains were about 20,000 pieces of human remains were collected, a database of the victims’ DNA profiles collected, a database of the victims’ DNA profiles was created was created

Super Bowl XXXIV FootballsSuper Bowl XXXIV Footballs Marked with invisible, yet permanent, strand of Marked with invisible, yet permanent, strand of

synthetic DNAsynthetic DNA 2000 Summer Olympic Souvenirs2000 Summer Olympic Souvenirs

Human DNA (Australian athletes) added to Human DNA (Australian athletes) added to inkink used used to mark all official goods to mark all official goods

What is DNA What is DNA Fingerprinting used for?Fingerprinting used for? Identify endangered and protected species as an Identify endangered and protected species as an

aid to wildlife officials (could be used for aid to wildlife officials (could be used for prosecuting poachers) prosecuting poachers)

Detect bacteria and other organisms that may Detect bacteria and other organisms that may pollute air, water, soil, and food pollute air, water, soil, and food

Match organ donors with recipients in transplant Match organ donors with recipients in transplant programs programs

Determine pedigree for seed or livestock breeds Determine pedigree for seed or livestock breeds Authenticate consumables such as caviar and Authenticate consumables such as caviar and

wine wine