DNA purification Sample Clauses

DNA purification. During the DNA shearing preparation the Agencourt AMPure XP Beads were left to come up to room temperature for at least 30 minutes prior to the purification. The reagent was then mixed well so that it became homogenous. 180 μl of AMPure XP beads were pipetted into each 1.5 ml LoBind tube and the sheared DNA library (~130 μl) was added. The mix was vortexed and incubated for 5 minutes. The tubes were placed on a magnetic stand until the solution appeared clear (3-5 minutes). While keeping the tubes on the magnetic stand the entire cleared solution was discarded making sure the beads were left untouched. The tubes were kept on the magnetic stand while 500 μl of freshly constituted 70% ethanol were dispensed into each tube. The tubes were left to rest for 1 minute to allow any disturbed beads to settle and then ethanol was removed. The ethanol step was repeated once more for optimum results. The samples were left to dry on a heat block set at 37 oC for 5 minutes or until the ethanol had completely evaporated making sure though that no cracking was formed in the bead pellet. 50 μl of nuclease-free water were added to each tube and the solution was mixed well on a vortex mixer and then incubated for 2 minutes at room temperature. The tubes were placed back on the magnetic stand and left for 3 minutes until the solution cleared. The 50 μl of the supernatant were removed to a new 1.5 ml LoBind tube and used beads were discarded.