3. Restriction maps show the lengths of DNA fragments

•After cut into fragments….
-Studied
-DNA is placed in other organisms

•BUT FIRST- DNA fragments are separated from one another by size by a technique called electrophoresis

•Gel Electrophoresis- DNA is loaded into gel (like hard gelatin) with a positive charge on one side and a negative charge on the other end. DNA has a negative charge, so the fragments move to the positive electrode.

•Gel has tiny pores to allow small molecules to travel fast through the gel. However, the big pieces will move slowly.

•Length of the DNA fragment is estimated by distance traveled through the gel in a certain period of time

•Lengths showed by restriction maps

•Study lengths to mind mutations- mutations change lengths and restriction sites
Example- If normal DNA has 5 bands, and DNA Strand A has only 3, then that one has mutated.