NPPOC vs. SPh-NPPOC comparison

In order to make direct comparisons between syntheses using NPPOC vs. SPh-NPPOC, we designed a microarray with probe replicates synthesized using NPPOC phosphoramidites as well as probe replicates synthesized using SPh-NPPOC phosphoramidites. Because all the monomer ports of the Expedite 8909 may not work equally well, the Sph-NPPOC synthesis was performed first, and paused while the monomer ports were cleaned out and filled with NPPOC phosphoramidites. The synthesis of the second set of microarray probes was then continued on the same surface. The location of each set of probes was randomized across the microarray surface. The experiment was performed using 7, 34 and 70 mW/cm² light exposures for the SPh-NPPOC amidites and using 1 or 4 % (w/v) imidazole in DMSO (Fig. 7). Because the probe set synthesized with SPh-NPPOC was performed first, the actual relative performance of SPh-NPPOC is likely ~6 % better than indicated in Fig. 7.