“For DNA Synthesis” Reagent Grade — Detailed Explanation & Rationale
“For DNA Synthesis” Reagent Grade — Detailed Explanation & Rationale
What is the “for DNA synthesis” grade?
"For DNA synthesis" is a functional grade formulated specifically for oligonucleotide (oligo) chemical synthesis and related enzymatic workflows. It is not merely “higher purity”; it prioritizes trace-level attributes that directly influence coupling reactions:
(a) Ultra-low water content (typically KF ≤ 10 ppm) and minimal acidic/reactive impurities
(b) Lot-to-lot consistency, with proven compatibility with phosphoramidite chemistry or enzymatic systems
(c) Control of trace metals, peroxides, particulates, and other factors that can stall reactions
Who defines it?
There is no global, mandatory standard. Grades are generally supplier-defined and specified on the COA/technical datasheet (e.g., “≥99.9% (GC), KF ≤ 10 ppm, 1 μm filtration”). When you receive a solvent or reagent labeled “for DNA synthesis,” the key is to check whether the COA metrics align with your process window.
Why is it necessary?
In oligonucleotide synthesis, each step’s coupling efficiency accumulates multiplicatively into the final full-length product fraction. If per-step efficiency is E, the ideal full-length yield after n steps approximates Eⁿ. Thus, raising a single-step efficiency from 99.0% to 99.5% (a 0.5-point increase) is exponentially amplified over dozens of steps, producing substantial differences in final product quality and length distribution. Among the most sensitive determinants of coupling efficiency are water and inhibitory impurities—they scavenge reactive groups, trigger premature deprotection (e.g., early loss of DMT), and introduce N–1 deletions. Therefore, controlling ppm-level water and inhibitors is the fundamental value of the “for DNA synthesis” grade.
Routine QC Items for “For DNA Synthesis” Reagents
I. Solvents (e.g., acetonitrile, dichloromethane, THF)
1. Water (Karl Fischer): typical limit ≤ 10 ppm (critical).
2. Purity (GC): typically ≥ 99.9%.
3. Acidity/basicity (reported as acetic acid, etc.); peroxides (especially for ether/THF systems).
4. UV absorbance / non-volatile residue (NVR) / volatile impurities; trace metal ions (ICP-MS).
Notes:
(i) Solvents are the reaction medium—every step occurs in them. Specs such as KF ≤ 10 ppm, ≥ 99.9% (GC), low acidity/carbonyls/metals, and 1 μm filtration markedly reduce failure rates and mitigate column clogging/particulate issues.
II. Key Synthesis Reagents/Solutions (Chemical Steps)
1. Activators: tetrazole derivatives (ETT, BTT), 4,5-dicyanoimidazole (DCI), etc. — monitor purity, water, stability.
2. Oxidizers: classical I₂/H₂O/pyridine/THF systems; for substrates sensitive to water/iodine, consider anhydrous oxidation systems — monitor formulation concentration and sensitivity to water/halogens.
3. Detritylation (DMT removal): DCA/DCM solutions — monitor acidity and water.
4. Capping: acetic anhydride with auxiliaries (e.g., NMI or 2,6-lutidine) — monitor formulation strength and amine/water traces.
5. Thioation: Beaucage reagent, DDTT, etc. — monitor purity/stability (light/moisture sensitive).
Notes:
(a) Role of activators/formulated reagents: activate the phosphoramidite monomer so it couples rapidly and cleanly to the solid-phase 5′-OH. Activators are highly sensitive to water/acid/metals; impurities drive side reactions, self-polymerization, and clogging.
(b) Role of oxidizers/alternative oxidation systems: convert newly formed P(III) to P(V) to stabilize the internucleotide linkage. Trace-level changes (water, halogens) in the oxidizer system can erode protecting groups or introduce side products.
(c) Roles of detritylation/capping/thioation:
(i) Detritylation: exposes 5′-OH to prepare for the next coupling.
(ii) Capping: permanently blocks unreacted 5′-OH, preventing mis-extension in the next cycle (reduces minor peaks).
(iii) Thioation: replaces P=O with P=S (phosphorothioate, PS) to enhance nuclease resistance and related properties.
(iv) Why use “for DNA synthesis” grade: acidic/amine/sulfur reagents are especially sensitive to water/acid/metals; impurities can cause strand scission and side reactions.
III. Monomers & Modifications (amidites/supports)
1. Chemical purity, isomers/deprotection by-products, reactivity (NMR/LC/titration), water/acid sensitivity; where necessary, perform on-instrument functional tests.
Notes:
(i) Function: supply protected A/T/C/G nucleosides and functional modifications such as 2′-F, 2′-OMe, MOE, LNA, GNA.
(ii) Why “for DNA synthesis”: these monomers are highly susceptible to water/acid/metal traces; even slight instability leads to degradation, self-polymerization, or coupling failure.
IV. Enzymes & Buffers (Enzymatic DNA Synthesis, Ligation, etc.)
1. Activity (U/μL), DNase/RNase/Protease negative, endotoxin limits, mycoplasma testing (if cell-related upstream work is involved).
Notes:
(i) While not part of phosphoramidite coupling, workflows such as ligation/restriction/RT/IVT must meet: DNase/RNase/Protease negative, low endotoxin, stable unit activity, and reproducible buffer systems.
Aladdin Product List
Category | Sub-category | Cat. No. | Name | CAS | Grade / Purity | Function & Why “for DNA Synthesis” |
Monomers / Modified Nucleosides | 2′-F (amidite) | 2′-F-dC(Bz) phosphoramidite | 161442-19-9 | For DNA synthesis, molecular biology grade, ≥98% | 2′-F is extremely sensitive to water/acid; low water/acid and low inhibitors markedly improve coupling and reduce N−1. | |
Monomers / Modified Nucleosides | 2′-F (protected nucleoside) | 5′-DMT-2′-F-iBu-2′-deoxyguanosine | 144089-96-3 | For DNA synthesis, molecular biology grade, ≥98% | DMT + 2′-F systems are moisture/acid-sensitive; tight water/acid control prevents premature detritylation and side reactions. | |
Monomers / Modified Nucleosides | 2′-F (nucleoside / precursor) | N4-Ac-2′-fluoro-2′-deoxycytidine | 159414-97-8 | For DNA synthesis, molecular biology grade, ≥98% | 2′-F + Ac protection can drop early; strict control of water/acid/metal traces preserves downstream activation/coupling. | |
Monomers / Modified Nucleosides | 2′-F (protected nucleoside) | N4-Ac-5′-O-DMT-2′-F-dC | 159414-98-9 | For DNA synthesis, molecular biology grade, ≥98% | Maintains DMT/2′-F stability; high purity/low water reduce failed cycles and minor peaks. | |
Monomers / Modified Nucleosides | 2′-OMe (amidite) | 2′-OMe-G(dmf) phosphoramidite | 128219-77-2 | For DNA synthesis, molecular biology grade, ≥96% (mixture) | 2′-OMe is sensitive to inhibitory impurities; control water/acid/carbonyls to boost coupling and reproducibility. | |
Monomers / Modified Nucleosides | 2′-OMe (amidite) | 2′-OMe-G(iBu) phosphoramidite | 150780-67-9 | For DNA synthesis, molecular biology grade, ≥98% | High purity/low water reduces deprotection/thioation side products; improves yields and eases purification. | |
Monomers / Modified Nucleosides | 2′-OMe (amidite) | 5-Me-2′-OMe-C(Bz) phosphoramidite | 166593-57-3 | For DNA synthesis, molecular biology grade, ≥97% (mixture) | ≥97% purity + low water substantially lower N−1/shortmers; better lot consistency. | |
Monomers / Modified Nucleosides | 2′-OMe (protected nucleoside) | 5′-DMT-Ac-2′-OMe-C | 199593-08-3 | For DNA synthesis, molecular biology grade, ≥98% | DMT + 2′-OMe requires low water/acid to preserve activation/coupling activity and repeatability. | |
Monomers / Modified Nucleosides | MOE (amidite) | 2′-O-MOE-G(iBu) phosphoramidite | 251647-55-9 | For DNA synthesis, molecular biology grade, ≥98% | MOE is sensitive to water/acid and metal traces; ensures high coupling with fewer side reactions. | |
Monomers / Modified Nucleosides | MOE (amidite) | 2′-O-MOE-U phosphoramidite | 163759-97-5 | For DNA synthesis, molecular biology grade, ≥98% (mixture) | Water/acid control reduces degradation during oxidation/detritylation; increases full-length fraction. | |
Monomers / Modified Nucleosides | MOE (amidite) | 5-Me-2′-O-MOE-U phosphoramidite | 163878-63-5 | For DNA synthesis, molecular biology grade, ≥98% (mixture) | Low water/acid/metal inhibitors safeguard coupling activity and inter-lot consistency. | |
Monomers / Modified Nucleosides | MOE (protected nucleoside) | DMT-MOE-iBu-rG | 251647-50-4 | For DNA synthesis, molecular biology grade, ≥98% | DMT + MOE are ultra-sensitive to trace water/acid; reduces over-detritylation/oxidation side products. | |
Monomers / Modified Nucleosides | MOE (protected nucleoside) | DMT-MOE-T | 163759-50-0 | For DNA synthesis, molecular biology grade, ≥96% | Maintains DMT/MOE stability during cycles and activation efficiency. | |
Monomers / Modified Nucleosides | MOE (base / precursor) | 5-methyl-2′-methoxyethoxy cytosine | 244105-55-3 | For DNA synthesis, molecular biology grade, ≥98% | Modified bases are more inhibitor-sensitive; high purity/low water yields cleaner length distributions. | |
Monomers / Modified Nucleosides | LNA (amidite) | 2′-O-4′-C-Locked-T phosphoramidite | 206055-75-6 | For DNA synthesis, molecular biology grade, ≥98% (mixture) | LNA is extremely sensitive to acid/water/metal traces; trace control ensures coupling activity and reproducibility. | |
Monomers / Modified Nucleosides | LNA (amidite) | LNA-Bz-A phosphoramidite | 206055-79-0 | For DNA synthesis, molecular biology grade, ≥98% (mixture) | High purity/low water reduces side reactions and chain termination; raises full-length content. | |
Monomers / Modified Nucleosides | LNA (amidite) | LNA-Me-Bz-C phosphoramidite | 206055-82-5 | For DNA synthesis, molecular biology grade, ≥98% | Strict control of inhibitors/water preserves coupling efficiency and downstream compatibility. | |
Monomers / Modified Nucleosides | GNA (amidite) | N6-Bz-A-(S)-GNA phosphoramidite | 851050-24-3 | For DNA synthesis, molecular biology grade, ≥98% | GNA relies on stringent trace-impurity control; fewer failed cycles and minor peaks. | |
Monomers / Modified Nucleosides | GNA (amidite) | T-(S)-GNA phosphoramidite | 168332-13-6 | For DNA synthesis, molecular biology grade, ≥98% | Low water/acid/metal inhibitors improve coupling success and sequence integrity. | |
Monomers / Modified Nucleosides | Other protected nucleoside | DMT-DMF-dG | 40094-22-2 | For DNA synthesis, molecular biology grade, ≥98% | DMT protection is moisture/acid-sensitive; ensures coupling activity and lot consistency. | |
Monomers / Modified Nucleosides | Other protected nucleoside (MOE precursor/intermediate) | DMT-MOE-5-Me-Bz-rC | 182496-01-1 | For DNA synthesis, molecular biology grade, ≥98% | Complex protection sets require tight water/acid/metal control to avoid side reactions/degradation. | |
Monomers / Modified Nucleosides | Special monomer (5-Me-dC amidite) | 5-Me-Bz-dC Phosphoramidite | 105931-57-5 | For DNA synthesis, molecular biology grade, ≥98% (mixture) | Bz + DMT combo is water/acid-sensitive; high purity/low water increases yields. | |
Monomers / Modified Nucleosides | Special substrate | 7-TFA-ap-7-Deaza-dG | 666847-77-4 | For DNA synthesis, molecular biology grade, ≥97% | Sterically hindered / deactivated substrate; low water/acid prevent degradation. | |
Monomers / Modified Nucleosides | Special substrate | 7-iodo-7-deaza-2′-deoxyadenosine | 114748-70-8 | For DNA synthesis, molecular biology grade, ≥97% | Halogenated substrates are impurity-sensitive; lowers side reactions/deactivation. | |
Monomers / Modified Nucleosides | Other special monomer (Ac-protected rG amidite) | Ac-rG phosphoramidite | 944138-03-8 | For DNA synthesis, molecular biology grade, ≥98% | Ac protection degrades under acid/water; low-acid/low-water environment ensures coupling and stability. | |
Enzymes / Enzyme Preps | Restriction endonuclease | BsaI | — | BioReagent, PCR reagent, for DNA synthesis, molecular biology grade, EnzymoPure™, for IVT, for DNA/RNA applications, 20 U/μL | Nuclease-free/low endotoxin/stable unit activity; reliable cleavage/assembly with reduced off-target cutting. | |
Enzymes / Enzyme Preps | Exonuclease | Exonuclease III | — | BioReagent, PCR reagent, for DNA synthesis, molecular biology grade, EnzymoPure™, for IVT, 100 U/μL | Free of non-specific nuclease contamination; more reproducible end processing. | |
Enzymes / Enzyme Preps | Restriction endonuclease | NruI | — | BioReagent, PCR reagent, for DNA synthesis, molecular biology grade, EnzymoPure™, for IVT, 20 U/μL | Tight impurity/buffer control reduces non-specific cutting and activity drift. | |
Enzymes / Enzyme Preps | RNase (high purity) | RNase R | — | BioReagent, DNase-free, PCR reagent, mycoplasma-tested, for DNA synthesis, molecular biology grade, EnzymoPure™, endonuclease, ≥95% (SDS-PAGE), 20 U/μL | DNase-free/mycoplasma-free/low endotoxin; cleaner background for IVT/analysis. | |
Enzymes / Enzyme Preps | Reverse transcriptase | RTL Reverse Transcriptase (glycerol-free) | — | BioReagent, PCR reagent, for DNA synthesis, molecular biology grade, EnzymoPure™, RNase-free, for IVT, 15 U/μL | RNase-free, low endotoxin; more stable and reproducible cDNA synthesis. | |
Enzymes / Enzyme Preps | Restriction endonuclease | SalI | — | BioReagent, PCR reagent, for DNA synthesis, molecular biology grade, EnzymoPure™, for IVT / Southern blotting, 20 U/μL | Unit activity/buffer matching lowers lot-to-lot variability. | |
Enzymes / Enzyme Preps | Ligase | T4 RNA Ligase 1 | — | BioReagent, PCR reagent, for DNA synthesis, molecular biology grade, EnzymoPure™, for DNA/RNA applications, 30 U/μL | Low nuclease/low endotoxin ensures ligation efficiency and reproducibility. | |
Enzymes / Enzyme Preps | Telomere / cutting-related enzyme | TelN Telomere Enzyme | — | BioReagent, PCR reagent, for DNA synthesis, molecular biology grade, EnzymoPure™, for IVT, 10 U/μL | Strict microbial/impurity control; suitable for in-vitro constructs. | |
Solvents | Primary coupling solvent (low water) | Acetonitrile (ACN) | 75-05-8 | For DNA synthesis, H₂O ≤ 10 ppm | Main coupling solvent; KF ≤ 10 ppm, low acidity significantly improves coupling and repeatability. | |
Solvents | Primary coupling solvent (high purity) | Acetonitrile (ACN) | 75-05-8 | For DNA synthesis, ≥99.9% (GC) | High purity/low water/low inhibitors reduce N−1 deletions and chain termination. | |
Activators / Formulations | Activator (ready-to-use) | T131637 | Tetrazole solution | 288-94-8 | For DNA synthesis, ~0.45 M in ACN, 1 μm filtered | Typical activator formulation; water-controlled and particle-filtered for stable activation with less clogging/side reactions. |
Selection Guidance
When should you choose the “for DNA synthesis” grade?
1. Chemical oligonucleotide synthesis/modification
Prioritize for DNA synthesis solvents and auxiliaries—especially acetonitrile (primary coupling solvent), DCM (for detritylation/wash), activators, and oxidizer/capping solutions.
Why: Conventional chromatography/HPLC grades focus on analytical background and do not guarantee the low-water, low-acid, and trace-inhibitor windows needed for phosphoramidite chemistry, which can depress coupling efficiency and final yield.
2. Bases or linkages sensitive to water/iodine
Prefer anhydrous oxidation systems (e.g., CSO-type), and apply extra control over solvent water content and halogen sensitivity.
3. Enzymatic workflows (ligation/restriction/amplification/RT/IVT)
Select enzymes and buffers labeled “molecular biology grade / EnzymoPure™ / nuclease-free / low endotoxin,” and maintain the recommended buffer system and unit activity.
Reminder: HPLC/LC-MS grade ≠ for DNA synthesis grade. The former is optimized for clean detection; the latter is optimized for reaction performance. Don’t conflate the two.
5-Step Quick Selector
1. Identify the workflow: chemical synthesis (coupling/oxidation/capping…) or enzymatic (ligation/restriction/RT/transcription)?
2. Start with solvents: for the primary coupling solvent ACN, choose for DNA synthesis (KF ≤ 10 ppm or ≥ 99.9% (GC)).
3. Match monomers: for 2′-F / 2′-OMe / MOE / LNA / GNA and related modifications, choose for DNA synthesis grades and review the COA (water, purity, impurity notes).
4. Activation/oxidation: for newer users, prefer ready-to-use formulations (pre-filtered / water-controlled) to reduce uncertainties from in-house mixing and mitigate particle-induced column clogging.
5. Enzymatic quality bar: select EnzymoPure™ / molecular biology grade / nuclease-free / low endotoxin; follow the manufacturer’s recommended buffer and temperature conditions wherever possible.
FAQ
Q1: Why must acetonitrile be “for DNA synthesis”?
A: Water, acids, and trace carbonyls severely inhibit phosphoramidite coupling, driving cumulative failure. For DNA synthesis ACN typically specifies ≥ 99.9% (GC) and H₂O ≤ 10 ppm, with controlled inhibitor profiles—significantly improving yield and run-to-run reproducibility.
Q2: Can HPLC-grade solvents substitute?
A: Not recommended. HPLC/LC-MS grades target chromatographic/mass-spectrometric cleanliness and do not ensure the low-water/low-acid and inhibitor limits required by phosphoramidite chemistry.
Q3: Do activators/oxidizers need the “for DNA synthesis” label?
A: Prefer formulations explicitly intended for oligo synthesis or high-purity reagents, and pay close attention to water content and stability.
Q
4: For enzymatic DNA steps (ligation/polymerization/IVT), what should I check?
A: Verify unit activity, DNase/RNase/Protease negative status, and endotoxin; when relevant, confirm mycoplasma-free. Corresponding Aladdin product pages list these labels and tests.
Q5: How do I verify lot quality?
A: Obtain/download the COA and confirm KF water, GC purity, acidity/NVR/UV absorbance, and where applicable metals/peroxides. For critical bulk lots, run a small-scale coupling-efficiency comparison as part of incoming inspection/fit-for-use qualification.
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