Why are there no oligos seen in the tubes?
Oligos are delivered either Iyophilized or in buffer/water in a concentration of 100 µM. in Iyophilized form, DNA is translucent and thus not wisible to the naked eye. Depending on how the Oligos is dried, it could appear as a clear film at the bottom of the tube(not apparent to the naked eye). Sometime, it could appear as puffy pellet. The puffy pellet is a result of formation of ice during the final dry-drown process where all the water is eventually dried off, leaving the oligos to retain the structure of ice crystals. Regardless of how the oligos appear in the tube, you need to re-suspend them before using. Always spin-down the tubes before opening as the oligos could be dislodged during transportation.
