Hello, Thanks for reading the article and for your positive comment. When one assembles a 20-mer with a stepwise yield of 98%, the yield of the full-length oligonucleotide is (0.98)^19 = 68.12%. This is the yield based on DMT assay; it does not account for depurination, base modifications, and purification/handling losses that make the isolated yield lower yet. So, the figure of 50-80% that you found in literature is correct. That's the yield you expect when your synthesizer works well. Cleavage from CPG: Most linkers/solid supports use succinyl arm. When oligonucleotides assembled on these supports are treated with conc. aqueous ammonium hydroxide for 2 h at room temperature, the expected yield of the release is >95%. If you want to release more, you can heat a suspension of solid support-bound material in conc. ammonia for 6-8 h at 65-80oC. This will complete the release and the removal of base-protecting groups. Heating will also dissolve noticeable amount of CPG. After ammonia is removed by evaporation, you will see gel-like, water-insoluble amorphous glasson the walls of the evaporation flask. You can remove the amorphous glass by dissolving the oligo in water or in an aqueous buffer and filtering the solution through a 0.2 um filter. Neither CPG nor PS are really expensive on large scale. When you purchase small quantities, that's a different story. You can load your own CPG, then it will be much cheaper. It does not take a lot of time, either. Best, Chemist234 (talk) 23:37, 10 September 2012 (UTC)Chemist234
Min 60% DVB is a fact of life. One can contact manufacturers of solid supports and verify with them. Chemist234 (talk) 20:09, 13 September 2012 (UTC)
EDA conditions were introduced by Prof. Paul Miller's group in early 1990's. I did not include EDA deprotection in the article because I consider these (and many other) conditions as methods for an advanced user. The article, however, is written for a beginner, that is, an undergrad chemist who has to get a crash course of oligo synthesis. With the present edition, I've been blaimed more than once for contents too complex for general public. So, I'm thinking may be they are right, and one should not make it more complex yet. However, if you feel that it is imporant to have EDA deprotection in the article, you are very welcome to add it. Best, Chemist234 (talk) 22:11, 14 September 2012 (UTC)