Taq DNA Polymerase PCR Buffer (10X)

Oligos should be run on a polyacrylamide gel containing 7 M urea and loaded with a 50% formamide solution to avoid compressions and secondary structures. Oligos of the same length and different compositions can electrophorese differently. dC's migrate fastest, followed by dA's, dT's, and then dG's. Oligos containing N's tend to run as a blurry band and generally have a problem with secondary structure.

Primers should be aliquoted for single use before PCR set-up. Heat just the aliquoted primers to 94 degrees for 1 min. Quick chill the primer on ice before adding to the PCR reaction. Some primers may anneal to themselves or curl up on themselves.

The drying method dries the primer in a thin layer along the sidewalls of the tube instead of the bottom, therefore a pellet is not always visible and should still be ready to use.

If the oligo was overheated, it will appear as a “ball”-shaped pellet attached to the bottom of the tube. This should not affect the quality of the oligo, and the oligo should be readily soluble in water.

If an oligo appears green in color, this is most likely due to ink falling into the tube. The oligo should still be fully functional. The color can be removed by doing an ethanol precipitation.