A Handful of DNA This hand contains a lot of DNA but we can’t see it.

A Handful of DNA

• This hand contains a lot of DNA but we can’t see it.

The more closely we look at the hand, the more details we can see.

Tiny building blocks called cells make up your skin, and every other part of you. Thousands of cells surround every hair growing out of your skin. The cells are in the light purple area at the base of the growing hair. To find the DNA, we have to look more

closely at the skin cells.

Different kinds of cells make up different parts of your body. You have fat cells, muscle cells, and skin cells. If you look closely you can see the dark-staining nucleus of these cells. The DNA is smaller still....

skin cells

There is DNA in nearly all of your cells, held in a sack called a nucleus. A nucleus is like the brain of the cell. It is where the cell stores all of the information it needs.

If you made a little hole in the nucleus sack, you would see DNA peeking through. If you took away the outside of the nucleus, the DNA would spill out like spaghetti.

Deoxyribonucleic acid

DNADe oxy ribo nucleic acid

An instruction manual for life

DNA has information about your hair:

•What colour•How long•Curly or straight

brown

curly shin

ybrown

shinycurly

But also….

• Your eye colour• Height• Shoe size• Skin colour• Freckles• Need glasses• Personality traits• Who your parents are

1.70m tall

blue eyes

Size 6

fair

Short sightedblon

de

DNA contains lots of information about you

• Everyone has information about the same things

• So everyone’s DNA is different, just like your fingerprints are different from others

• Scientists have found ways to compare people’s DNA

Brown hair

Brown skin

Short

sighted

Blonde hair

Fair skin

Good eye sight

Sir Alec Jeffrey

The scientist who invented DNA fingerprinting

Loading a well

Use a fresh tip45° angleSide onJust break surface of liquidGently expel DNADon’t puncture well!

Prepare to load gel

• Add 5µl Loading dye to each sample

• Add 10µl size marker (M) DNA to one well

• Add 20µl DNA to adjacent wells

• Run 20 minutes 200V

1 2 3 4 5 6 7 8

DNA

RULER

10µl

CRIME

SCENE

20µl

SUSPECT

1

20µl

SUSPECT

2

20µl

SUSPECT

3

20µl

SUSPECT

4

20µl

SUSPECT

5

20µl

EMPTY

DNA Electrophoresis - Setting up the Apparatus

DNA Electrophoresis - Movement of DNA Fragments

Tray located on tank platform

Wells nearest negative pole

Cardiff 3

The room where the murder took place.

Man was charged with murdering Cardiff woman 17 years ago.

http://pgs-dna.com/

Tahini-

The Genetic Donor

Tabouli and Baba Ganoush

The Clones

Stain gel

• Cover gel with Fast Blast DNA stainLeave 2 to 3 minutes

• De-stain in warm water Agitate gentlyLeave for 10 to 15 minutes

• Decide who is the culprit?