Protocol for Annealing Oligonucleotides

Oligo Name:

Lot Number:

Total nmol:

Volume of Annealing Buffer added:

Oligo Name:

Lot Number:

Total nmol:

Volume of Annealing Buffer added:

Annealing Buffer: 10mM Tris, pH 7.5 - 8.0, 50mM NaCl, 1mM EDTA

1xTE Buffer: 10mM Tris, pH 7.5 - 8.0,1mM EDTA

1.	Resuspending the Oligonucleotides: Resuspend both complementary oligonucleotides at the same molar concentration, using Annealing Buffer (see note below). For convenience, keep Annealing Buffer volume below 500ml for each oligo. Annealing should perform well over a wide range of oligo concentrations. For larger scale oligo syntheses, it may be necessary to use larger volumes that can be aliquoted after resuspension.
2.	Annealing the Oligonucleotides: Mix equal volumes of both complementary oligos (at equimolar concentration) in a 1.5ml microfuge tube. Place tube in a standard heatblock at 90 - 95ºC. Remove the heatblock from the apparatus and allow to cool to room temperature (or at least below 30ºC) on the workbench. Slow cooling to room temperature should take 45-60 minutes. Store on ice or at 4ºC until ready to use. An alternative procedure for annealing involves the use of a thermal cycler. Dispense 100ml aliquots of the mixed oligos into PCR tubes (500ml size). Do not overlay the samples with oil. Place the tubes in a thermal cycler and set up a program to perform the following profile: (i) heat to 95ºC and remain at 95ºC for 2 minutes, (ii) ramp cool to 25ºC over a period of 45 minutes, (iii) proceed to a storage temperature of 4ºC. Briefly spin the tubes in a microfuge to draw all moisture from the lid. Pool samples into a larger tube, store on ice or at 4ºC until ready to use.
3.	Long Term Storage. It may be necessary to aliquot and lyophilize the annealed sample. After drying, the sample may be stored at -20ºC in a desiccated container. Resuspend the annealed oligos at the desired concentration with sterile distilled water. The annealed pair of oligonucleotides is ready for use.

NOTE: Oligos may also be resuspended in either 1x Ligase Buffer or 1x Kinase Buffer instead of the above Annealing Buffer (prior to annealing).