What is DNA fingerprinting?

1. What is DNA fingerprinting? • A test to identify and evaluate genetic information (DNA) • It is called fingerprinting since it is unlikely for 2 individuals to have the same DNA • Only a small sample is usually needed.

2. How is DNA fingerprinting done? • DNA must be copied • DNA must be restricted • DNA must be separated by gel electrophoresis then analyzed

3. What is DNA restriction? • The cutting of single or double stranded DNA molecules at specific nucleotide sequences (recognition site). • Enzymes called endonucleases or restriction enzymes are used to restrict (cut) the DNA into fragments.

4. Restriction enzymes • Very specific • Will not work if the full recognition site is not present • Produce DNA fragments of various lengths. • Work at specific pH and temperature

5. Types of ends of restricted DNA • Blunt ends • Sticky ends

6. In the early 1970's, scientists discovered that bacteria had enzymes that would attack foreign DNA and cut the DNA up into little pieces. The sentence above represents a length of DNA isolated from a certain person. The restriction enzyme called TH1--with the recognition sequence "the," cuts between "h" and "e" in the sequence 'the'.

7. What would happen if the DNA molecule was treated with the TH1 enzyme? How many fragments will be formed? If each letter represented a base, how many bases would be in each fragment?

8. Here’s how its done In the early 1970's, scientists discovered that bacteria had enzymes that would attack foreign DNA and cut the DNA up into little pieces.

9. Here are the answers! In th (4 bases) e early 1970's, scientists discovered that bacteria had enzymes that would attack foreign DNA and cut th (86 bases numbers include not apostrophe) e DNA up into little pieces (22 bases)