DNA Fingerprinting Class 832

LEGO Model of DNA DNA is a molecule in your body. It is a code, which stores instructions for building the “machines” in your body. It is a double helix. It is a millionth of a millimeter wide. In humans, a molecule of DNA is 200,000,000 bases long.

DNA is a Code GGAAAACTAAC CCTTTTGATTG The genetic code is written in A’s, T’s, C’s and G’s. The sequence of A’s, T’s, C’s and G’s uniquely identifies a person, unless they are a twin. That’s why it’s called DNA fingerprinting.

Restriction Enzymes are Molecules that Cut DNA at Particular “Words”

Restriction Enzyme Cuts Yield Different Sized DNA Fragments 11102

Gel Electrophoresis is Used to Separate the Fragments Based on Size

Example DNA Fingerprint Column in Gel corresponds to a person’s DNA. It is called a person’s DNA fingerprint. Row corresponds to DNA fragment size.

Different People Have Different Restriction Enzyme Cut Sites Resulting in different band patterns on a gel. 1 2 Resulting in different sized DNA fragments.

Who did it? Solving a Murder Mystery Using DNA Fingerprinting

Given crime scene DNA and suspect DNA you will construct a gel. You will then analyze the gel to find a match between the crime scene DNA and a suspect’s DNA. You will use this information to make inferences about the murders. Solving Our Murder Mystery Using DNA Fingerprinting