Chapter 20
microcentrifuge (optional)
37 °C water bath
thermometer
1 g agarose
paper boat
electronic balance
500 mL Erlenmeyer flask
250 mL graduated cylinder
microwave or hot plate
flask tongs or oven mitts
gel casting tray and gel electrophoresis box
1L 1TBE buffer
5 L loading dye
power supply (45 V)
plastic wrap
25–30 mL 0.025 % methylene blue, or enough to cover the
gel in the staining tray
light box or overhead projector
acetate sheet
Wear safety goggles at all times.
Wear gloves when performing the experiment.
Wipe down all surfaces with 70 % ethanol, or 10 %
bleach, before and after the laboratory exercise.
Do not use ethanol near a heat source.
Wash your hands thoroughly at the end of the
laboratory.
Procedure
Day 1: Restriction Enzyme Digestion
- Put on your safety goggles and gloves, and wipe
down your bench with a 70 % ethanol solution
(or 10 % bleach).
INVESTIGATION 20.2continued
Table 1 Reagents to Add to Tubes
Tube DNA 10 Water BamHI EcoRI HindIII
(L) buffer (L) (L) (L) (L)
(L)
BamHI 41 4 1
EcoRI 41 4 1
HindIII 41 4 1
control 41 5
Ethanol is highly flammable. Make sure that any
flame on your desk or near it is turned off before use.
- Label four 1.5 mL Eppendorf tubes “BamHI,”
“EcoRI,” “HindIII,” and “control.” Place the tubes in a
polystyrene cup containing crushed ice.Table 1
outlines the amount of reagents to add to each tube.
To keep track of each tube’s contents, copy the table
into your notebook and check off each reagent as you
add it to the tube. - Read down each column, adding the same reagent to
all appropriate tubes. Use a fresh tip on the
micropipette for each reagent. Add the 4 L of DNA
to each tube first, followed by the 10reaction
buffer, and then the water.Make sure you add the
enzyme last. Dispense all the contents close to the
bottom of the Eppendorf tubes. Ensure that the
pipette tip is touching the side of the tubes when
dispensing the contents.Keep everything on ice at all
times. - Close the Eppendorf tube tops. Place the tubes in the
microcentrifuge, close it, and spin at maximum speed
for approximately 3 s. If you do not have access to a
microcentrifuge, then just tap the tubes on a soft pad
or thick paper towel on the bench, pooling the
contents to the bottom.
NEL Molecular Genetics 697
0
5 505
EcoRI EcoRI EcoRI EcoRI EcoRI
31 747 34 499 39 168 41 732
48 500
23 132
21 226
22 346
HindIII HindIII HindIII
BamHI BamHI BamHI BamHI BamHI
37 495
36 895
44 972
44 141
27 479
25 157
26 104
27 972 37 584
Figure 1
Restriction enzyme map of bacteriophage lambda DNA