DNA FINGERPRINTING

DNA FINGERPRINTSDNA can be collected from any living tissue:blood, skin, hair, urine, semen, sweat or tears

Gel Electrophoresis:1. DNA sample is inserted into a well of a

gel. Agar gel is used; agar is from seaweed

and is electrically neutral

2. An electric current is passed through the gel and buffer solution

The negatively charged particles of the DNA move toward the positive electrode while the positive charge particles move toward the negative electrode.

Gel Electrophoresis:3. Shorter strands move

farther down the gel as pieces of DNA separate & show up as bands

4. Gel or DNA is stained to make the bands more visible

5. Samples are compared to find a match

III. Gel Electrophoresis- How

does it work? DNA is negatively charged so it is attracted to the positive end of the gel.

The shorter DNA fragments move faster than the longer fragments.

DNA is separated on basis of size.

IV. USES:1. Paternity & Maternity

cases2. Criminal investigations

DNA or other genetic evidence left at the scene of a crime can be compared

3. Personal identification Missing person,

remains of a body

V. Who committed the crime?

Suspect #2-They are a matc

h!

V. Who committed the crime?

Suspect #1-They are a matc

h!