a handful of dna this hand contains a lot of dna but we can’t see it
TRANSCRIPT
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.
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?