Practice English Speaking&Listening with: Gel Electrophoresis

Difficulty: 0

Raise the end gates on the gel tray and tighten the screws.

Using a hand protector, obtain a flask of hot agarose from the incubator.

Pour enough agarose into the tray until it is just below the center notch on the tray.

Place the well comb in the outer notches of the tray.

Wait approximately 20 minutes for the gel to set.

The agarose gel has set if it is slightly cloudy when checked against a dark background.

Carefully pull the well comb straight up to remove it.

Do not discard the comb.

Hold the tray level so the gel doesn't slide off

and loosen the screws to lower the end gates.

Center the gel tray on the center platform of the electrophoresis chamber

so that the wells are on your left.

After placing the gel on a dark background within reach of the power supply,

add the running buffer.

First, fill both reservoirs.

Second, add enough buffer so that the gel is barely covered.

Third, make sure the sample wells are immersed.

When your samples are ready, load each one into the gel

using a fresh tip for each sample.

Place your elbows on the table to steady your hands.

Hold the micropipettor steady and insert the tip so that it is just barely into the well.

Carefully depress the plunger to the first stop and then to the second stop to release the sample.

The dye should fall into the well.

Remove the micropipettor without touching the gel.

Discard the used tip into the tip discard container.

Align the gel lid with both electrodes and use 2 hands to push it into place

so that you do not bend the electrodes.

Before plugging in the power supply, check its settings.

They should be set as shown. The power switch is turned off,

the voltage knob is turned to minimum,

the range is set to low,

and the display switch is set to volts.

Also, the electrode cables should be plugged in as shown.

After obtaining your TA's approval, plug in the power supply.

Turn on the power supply and set the voltage to 100-103 volts by turning the control knob.

Once the current is running through the electrophoresis chamber small bubbles begin to form near the samples.

About an hour to an hour and a half later, after your samples have finished running,

turn off the power supply and unplug it.

Unplug the electrodes from the power supply and remove the lid.

Carefully remove the gel tray. If you tilt the tray too much, your gel will fall off the tray.

Raise the end gates and tighten the screws.

Pour off the excess buffer.

Open the lid of the transilluminator.

Place the gel on top and close the lid.

Turn on the transilluminator.

TAs, place the camera so that the magnetic safety switch on the camera hood

aligns with the magnetic safety switch in the front right corner of the transilluminator.

From here, the TA will take a picture of the DNA fingerprint

and print it according to the instructions on the TA desk.

The Description of Gel Electrophoresis