4-6-5 DNA Fingerprinting: Who Dunnit?

Question 1

A brief definition of DNA fingerprinting

Answer 1

DNA fingerprinting uses the pattern of DNA fragment lengths, which results from cutting a sample of DNA using restriction enzymes, to identify individuals.

Question 2

Steps of DNA fingerprinting

Answer 2

1. Often, the DNA sample is amplified by PCR.
2. The DNA is treated with restriction enzymes, whcih cut it into fragments.
3. Gel electrophoresis is used to separate the DNA fragments according to length, producing a pattern of bands.

DNA sequences, especially in the intron regions, differ from individual to individual. When the DNA is cut by restriction enzymes, the resulting DNA fragment lengths vary from individual to individual, giving rise to band patterns that differ from individual to individual.

Genetically related individuals have band patterns that are more similar than individuals who are not genetically related.

Question 3

Some applications of DNA fingerprinting

Answer 3

Identify deceased individuals from skeletal remains

Identify perpetrators of crimes from blood or semen samples

Determine the genetic makeup of extinct organisms or long-dead individuals