- Materials
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- gDNA in 48 μl nuclease-free water
- Consumables
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- 0.2 ml thin-walled PCR tubes
- 1.5 ml Eppendorf DNA LoBind tubes
- Nuclease-free water (e.g. ThermoFisher, AM9937)
- NEBNext® Ultra II End Repair / dA-tailing Module (NEB, E7546)
- Agencourt AMPure XP beads (Beckman Coulter™, A63881)
- Freshly prepared 70% ethanol in nuclease-free water
- Equipment
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- P1000 pipette and tips
- P100 pipette and tips
- P10 pipette and tips
- Thermal cycler
- Microfuge
- Hula mixer (gentle rotator mixer)
- Magnetic rack
- Ice bucket with ice
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Prepare the DNA in nuclease-free water
- Transfer <1 μg (or <100-200 fmol) genomic DNA into a 1.5 ml Eppendorf DNA LoBind tube
- Adjust the volume to 48 μl with nuclease-free water
- Mix thoroughly by flicking the tube to avoid unwanted shearing
- Spin down briefly in a microfuge
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In a 0.2 ml thin-walled PCR tube, mix the following:
Between each addition, pipette mix 10-20 times.
Reagent Volume <1 µg DNA 48 µl Ultra II End-prep Reaction Buffer 7 µl Ultra II End-prep Enzyme Mix 3 µl Nuclease-free water 2 µl Total 60 µl -
Thoroughly mix the reaction by gently pipetting and briefly spinning down.
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Using a thermal cycler, incubate at 20°C for 5 minutes and 65°C for 5 minutes.
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Resuspend the AMPure XP beads by vortexing.
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Transfer the DNA sample to a clean 1.5 ml Eppendorf DNA LoBind tube.
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Add 60 µl of resuspended AMPure XP beads to the end-prep reaction and mix by flicking the tube.
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Incubate on a Hula mixer (rotator mixer) for 5 minutes at room temperature.
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Prepare 500 μl of fresh 70% ethanol in nuclease-free water.
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Spin down the sample and pellet on a magnet until supernatant is clear and colourless. Keep the tube on the magnet, and pipette off the supernatant.
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Keep the tube on the magnet and wash the beads with 200 µl of freshly prepared 70% ethanol without disturbing the pellet. Remove the ethanol using a pipette and discard.
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Repeat the previous step.
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Spin down and place the tube back on the magnet. Pipette off any residual ethanol. Allow to dry for ~30 seconds, but do not dry the pellet to the point of cracking.
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Remove the tube from the magnetic rack and resuspend the pellet in 61 µl nuclease-free water. Incubate for 2 minutes at room temperature.
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Pellet the beads on a magnet until the eluate is clear and colourless, for at least 1 minute.
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Remove and retain 61 µl of eluate into a clean 1.5 ml Eppendorf DNA LoBind tube.
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Quantify 1 µl of eluted sample using a Qubit fluorometer.