DNA fingerprinting
made simple
Cat no 130
Edvotek Europe
What are we
doing today?
• Introduction
• Prepare gels for loading
• Load samples
• Run gels
• Stain & analyse results
Why study DNA?
Ready to load kit
• 130 DNA fingerprinting made simple
– DNA based electrophoreis
– Needs staining to see result
Health & safety
• No toxic chemicals
• Safe solutions and reagents used in
place of research materials
Compare samples
• Use electrophoresis
• Micropipette to load samples
• Electrical current will separate by
size
• Pattern is DNA fingerprint
Gel casting
Running buffer
TAE buffer
• 20ml 50x buffer to 1 litre with water
• Distilled water ideal but tap ok
• Can be reused a few times
• Store unused for future use ok
Agarose
0.8% Agarose
• 3g in 375 ml dilute buffer
• Melt in microwave/autoclave
• Pour when hand hot
Agarose
• Store gels for 1-2 weeks in fridge
wrapped in cling film or plastic bag
• Keep any left over gels and remelt
next time
The experiment
Remove comb & ends
Fixed volume
minipipette
Adjustable
micropipette
Dry loading
• You can load gel dry instead of through
buffer!
• Otherwise load “wet” through buffer
Either way, remember
• Do not puncture bottom of well
• Change tips between each sample
HexaGel and EVT
300 power supply
130 kit gel Loading
Load 40 l of each sample into the wells
A
B
C
D
E
M
CS
S1
S2
S3
F
Run gels
• Put on lid and attach to power
supply
• Run for 30 minutes at 150 volts
• Or 75 volts for 40-50 minutes
• Check for bubbles at electrode
• Run until tracking dye halfway
across gel
Background on DNA
fingerprinting
How do you make
a DNA fingerprint
• Get DNA from someone
• Cut it up with enzymes
• Separate different size pieces on a
gel
• Pattern is a DNA fingerprint
Get some DNA
DNA is very long
• 2 metres per cell!
• 3 billion letters long (ACTG)
• Like a piece of string
• Cut with scissors
Where to cut?
• Decided by combination of letters
GTTAAC is cut by one sort of enzyme
TTAA cut by a different sort
Real enzymes
Separate on gel
• Made of seaweed - agarose
• Different size pieces move through
mesh - like a sieve
• Small move quicker than big
• Called DNA electrophoresis!
move by size
big
medium
small
Prof. Sir Alec Jeffreys
Invented DNA fingerprinting
First ever DNA fingerprint
What it means
M = mother
C = child
F = father
Child has bands in
Common with mother
& father
m
c
f
After gel run stain the gel
Stain 130 kit gel
• MetBlue card blue side down 5 mins
• Weigh with gel tray
• Destain in warm water 10-15 mins
• Leave overnight in fridge for best
result
• Keep long term in bag in fridge
Stain Gel
Gel storage
• Can store gels in fridge before staining
over weeknight or weekend
• Cannot store dye kits overnight before
viewing as diffuse!
130 kit result
M
CS
S1
S2
S3
Thank you
• DNA experiments can be carried
out easily
• Fun and relevant to wider world
• Promote understanding