Reusable solid-phase supports for oligonucleotides and antisense therapeuticsElectronic supplementary information (ESI) available: CGE data for octathymidine phosphodiester sequences on supports P1–5, P7, P9, and P11–13 PAGE data for phosphorothioate products, dimethoxytrityl analysis and UV measurements on supports P1–7, P9 and P15, step listing for ABI394 DNA synthesizer and CGE and HPLC data for phosporothioate syntheses on support P3. See http://www.rsc.org/suppdata/p1/b1/b105089n/
Bibliographic record
Abstract
A general method for oligonucleotide synthesis on reusable solid-phase supports has been developed which will significantly lower the cost of large-scale synthesis. It consists of five steps: 1, nucleoside attachment to an hydroxy derivatized support through a Q-linker (hydroquinone-O,O′-diacetic acid) linker arm; 2, chloro-acetylation of unreacted surface groups; 3, conventional phosphodiester or phosphorothioate oligonucleotide synthesis; 4, cleavage from the support with aqueous or anhydrous ammonia; and 5, support regeneration with methanolic potassium carbonate. The recycling process is fast, fully automatable, and does not require removal of the support from the synthesis column. Fifteen solid-phase supports were evaluated with glycerol-CPG providing the best results. Consecutive syntheses of ISIS 2302, a dGCCCAAGCTGGCATCCGTCA phosphorothioate sequence, on the same synthesis column were performed. A glycerol-CPG synthesis column was satisfactorily used six consecutive times when NH4OH was the cleavage reagent. However, anhydrous NH3 allowed twelve consecutive syntheses without any deterioration in support loading, product quality, or amount of product produced. An improved method for preparing the essential nucleoside-3′-hemiesters of the Q-Linker and an unexpectedly slower rate of cleavage for phosphorothioate DNA vs. phosphodiester DNA are also described.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.002 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.032 | 0.023 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".