DNA Molecular Weight Calculator

A DNA molecular weight calculator computes the molar mass (g/mol, equivalently daltons for a single molecule) of a single-stranded or double-stranded DNA fragment from its nucleotide sequence. The same calculation underlies three other quantities every molecular biologist reaches for daily, length in bases or base pairs, GC and AT content percentages, and melting temperature. Coupled with the 260 nm absorbance conversion (1 OD ≈ 33 µg/mL for dsDNA, 40 µg/mL for ssDNA / ssRNA), the tool bridges raw sequence, mass, moles, and concentration in one panel.

The calculation matters in practice because almost every molecular-biology workflow needs the molecular weight of an oligonucleotide before it can be ordered, quantified, diluted to a working concentration, or mixed into a reaction. PCR primers must have predictable Tm and GC content. qPCR probes must match their primer Tm. Gibson assembly oligos must be sized so the overhangs melt at compatible temperatures. NGS adapters must be ordered at a known copy number. Synthetic biology gRNAs must be quantified by mass. In every case the starting point is the molecular weight of the oligo derived from its sequence.

How to Use the DNA Molecular Weight Calculator

1. Paste the sequence into the sequence box. Use the four canonical IUPAC nucleotide codes A, C, G, T (case-insensitive, the calculator uppercases everything internally). Whitespace, line breaks, and FASTA-style header lines (>name) are stripped automatically. Numbers, ambiguous codes (N, R, Y, K, M, S, W, B, D, H, V) and any other characters are converted to N and counted separately so they cannot silently bias the result.
2. Choose a strand mode, single-stranded (ss) or double-stranded (ds). Single-stranded mode returns the mass of the input sequence as a single polymer. Double-stranded mode doubles the single-stranded mass and subtracts one water per base-pair terminus (the canonical correction). Double-stranded mode also switches the absorbance constant to 33 µg/mL instead of 40 µg/mL.
3. Optionally enable RNA mode to use the ribonucleotide monophosphate masses (AMP 347.22, UMP 306.17, GMP 363.20, CMP 323.20) and to swap T for U. RNA mode is useful when the sequence was synthesised as RNA, or when you want to compute the mass of an mRNA / gRNA / siRNA molecule.
4. Click Calculate. The result panel returns the molecular weight in g/mol (and Da), the length in bases (ss) or base pairs (ds), the per-base composition, the GC and AT percentages, the melting temperature using the Wallace rule for short oligos (≤ 14 nt) or the Marmur-style approximation for longer fragments, and the 260 nm absorbance conversion with mass per OD and nmol per OD.
5. Use the presets to load example sequences: a balanced 20-mer, a 100 bp ATGC-repeat fragment, a 1,000 bp fragment for dsDNA-mode testing, a GC-rich 10-mer, and an AT-rich 12-mer. Each preset is hand-verified and demonstrates a specific corner of the calculation.

The live preview above the result panel updates the cleaned length and GC / AT content on every keystroke so you can spot input mistakes before clicking Calculate. The full MW panel only updates after Calculate is pressed, which keeps the displayed numbers stable while you edit.

The Formula

For a single-stranded DNA sequence of length n nucleotides, the molecular weight is the sum of the molecular weights of the constituent deoxynucleotide monophosphate residues minus the water lost during phosphodiester bond formation:

MW_ss = Σ M(nucleotide_residue) − (n − 1) × M(H₂O)

The standard residue masses used here are the canonical textbook values found in Sambrook & Russell's Molecular Cloning, the Sigma-Aldrich technical bulletins on oligonucleotide properties, and the IDT OligoAnalyzer reference data:

• dAMP (deoxyadenosine monophosphate): 313.21 g/mol
• dTMP (deoxythymidine monophosphate): 304.20 g/mol
• dGMP (deoxyguanosine monophosphate): 329.21 g/mol
• dCMP (deoxycytidine monophosphate): 289.18 g/mol
• H₂O: 18.015 g/mol

The (n − 1) water correction comes from the fact that joining two nucleotides by a phosphodiester bond releases one water molecule. A chain of n nucleotides therefore contains (n − 1) such bonds.

For double-stranded DNA, by convention the molecular weight is the mass of one strand plus the mass of its complement minus the water lost at the two helix termini:

MW_ds = 2 × MW_ss − 2 × 18.015

This is the same answer the textbook gives as 660 Da per base pair (or the simplified 650 Da/bp rule) when averaged over a roughly balanced sequence. The "660 Da per bp" rule is exact only when the average base composition is balanced; AT-rich sequences run slightly lighter per bp (around 635 to 650 Da/bp) and GC-rich sequences slightly heavier (around 665 to 680 Da/bp) because G·C pairs have one extra hydrogen bond but only marginally different mass.

For GC and AT content, the formulas are simply fractions of the total unambiguous base count:

GC % = (nG + nC) / (nA + nT + nG + nC) × 100

AT % = (nA + nT) / (nA + nT + nG + nC) × 100

These sum to 100 % (within rounding) and use the unambiguous base count as the denominator so an N-containing sequence still produces a well-defined answer.

The melting temperature (Tm) is the temperature at which half the duplex has denatured into single strands. The simplest rule is the Wallace rule, valid for short oligos up to about 14 nt in roughly equimolar salt conditions:

Tm (Wallace) = 2 × (nA + nT) + 4 × (nG + nC)

Each A·T pair contributes 2 °C and each G·C pair contributes 4 °C because G·C pairs have three hydrogen bonds versus two for A·T pairs. For longer sequences the calculator switches to the Marmur-style approximation, which assumes roughly 1 M monovalent cation:

Tm (Marmur) = 64.9 + 41 × (nG + nC − 16.4) / n

For very accurate Tm on long sequences (especially for qPCR probe design) the field uses the SantaLucia 1998 unified nearest-neighbour parameters, which the calculator flags in the result panel as a future improvement.

The 260 nm absorbance conversion uses the well-established bench-science conventions:

1 OD₂₆₀ ≈ 33 µg/mL (dsDNA)

1 OD₂₆₀ ≈ 40 µg/mL (ssDNA / ssRNA)

Combined with the calculated molecular weight, the conversion to nanomoles per OD is:

nmol per OD = 1,000,000 / (mass_per_OD_µg_per_mL × MW_g_per_mol)

This is the value you multiply an OD₂₆₀ reading by to obtain the molar concentration of the oligo in solution.

Worked Examples

Example 1, A short 4-mer diagnostic

Sequence: 5′-ATGC-3′ (4 nucleotides, single-stranded).

Sum of residue masses:

Subtract (n − 1) waters: 1235.80 − 3 × 18.015 = 1235.80 − 54.045 = 1181.76 g/mol.

GC content = (1 G + 1 C) / 4 × 100 = 50.0 %. AT content = 50.0 %. Tm (Wallace) = 2 × (1 + 1) + 4 × (1 + 1) = 12 °C. Length = 4 nt. 1 OD₂₆₀ ≈ 40 µg/mL → nmol per OD = 1,000,000 / (40 × 1181.76) ≈ 21.16 nmol/OD.

Example 2, A 100 % GC short oligo

Sequence: 5′-GGCC-3′ (4 nucleotides).

Sum: 329.21 + 329.21 + 289.18 + 289.18 = 1236.78 g/mol. Subtract 3 waters: 1236.78 − 54.045 = 1182.74 g/mol.

GC content = 100.0 %, AT content = 0.0 %. Tm (Wallace) = 2 × (0 + 0) + 4 × (2 + 2) = 16 °C. Length = 4 nt.

Example 3, A 100 % AT short oligo

Sequence: 5′-AAAA-3′ (4 nucleotides).

Sum: 4 × 313.21 = 1252.84 g/mol. Subtract 3 waters: 1252.84 − 54.045 = 1198.80 g/mol.

GC content = 0.0 %, AT content = 100.0 %. Tm (Wallace) = 2 × (4 + 0) + 4 × (0 + 0) = 8 °C.

Example 4, A balanced 20-mer primer

Sequence: 5′-ATGCATGCATGCATGCATGC-3′ (20 nt, ssDNA). The composition is 5 of each base. Per-ATGC unit MW is 1181.76 g/mol (from Example 1), so for 5 ATGC units the linear scaling is roughly 5 × 1181.76 ≈ 5908.8 g/mol. The exact value is the sum of all 20 residues minus 19 waters: (5 × (313.21 + 304.20 + 329.21 + 289.18)) − 19 × 18.015 = 5 × 1235.80 − 342.285 = 6179.00 − 342.29 ≈ 5836.71 g/mol. Tm (Marmur, sequence length > 14) = 64.9 + 41 × (10 − 16.4) / 20 = 64.9 + 41 × (−0.32) = 64.9 − 13.12 ≈ 51.78 °C. GC % = 50 %.

Example 5, A 1,000 bp hypothetical fragment in dsDNA mode

Sequence: (ATGC) × 250 (1,000 nt, dsDNA mode). The single-stranded mass per ATGC tetranucleotide is 1181.76 g/mol, so 250 copies give an ssDNA mass of 250 × 1181.76 ≈ 295,440 g/mol. In dsDNA mode the mass is 2 × 295,440 − 2 × 18.015 ≈ 590,844 g/mol (≈ 590.8 kDa). This is consistent with the canonical 660 Da per bp average for balanced dsDNA (which would give 1,000 × 660 = 660,000 g/mol, slightly higher than the calculation above because the ATGC repeat is exactly balanced and ignores the small effect of having an integral repeat). 1 OD₂₆₀ ≈ 33 µg/mL → nmol per OD ≈ 1,000,000 / (33 × 590,844) ≈ 0.0513 nmol/OD.

Where the Calculation Shows Up

Primer design for PCR and qPCR. Every primer ordering form requires the sequence, the desired Tm, and the GC content. The molecular weight and the 260 nm conversion let the bench scientist prepare a 100 µM stock solution from a synthesis yield reported in mg or OD units. Tm matching between forward and reverse primers (typically within a few degrees) requires an accurate Tm formula, and the GC content (ideally 40 to 60 % for standard primers) is checked before ordering.

qPCR probe design. TaqMan or molecular-beacon probes are typically 20 to 30 nt long with a 5′ fluorophore and a 3′ quencher. The Tm of the probe should be roughly 7 to 10 °C higher than the Tm of the primers so the probe binds before extension. The Marmur / SantaLucia Tm formulas and the GC content are essential to getting this right. The molecular weight is also used to convert the moles of probe attached at the 5′ end back to a synthesis yield.

Oligonucleotide ordering from commercial suppliers. Suppliers like IDT, Sigma-Aldrich, and Thermo Fisher report synthesis yields in OD units or nanomoles and require a known molecular weight to verify the result. The 260 nm absorbance conversion bridges the supplier's reported yield and the user's intended working concentration.

NGS library preparation adapters. Adapter oligos are typically 30 to 60 nt long with a known sequence and known Tm. The molecular weight is needed to normalise adapter concentration before ligation, and the Tm is needed to design the ligation / PCR conditions so adapters melt at compatible temperatures.

Synthetic biology: gRNA, dsDNA donors, Gibson assembly oligos. CRISPR sgRNAs are typically 20 nt guide sequences followed by a constant scaffold. The mass and Tm of the variable portion are calculated independently. Gibson assembly overhangs are typically 15 to 40 nt long with sequence-dependent Tm and GC content.

mRNA vaccine and therapeutic design. In vitro transcribed mRNA is quantified by 260 nm absorbance and by molecular weight to set the dose in mg/kg. The molecular weight of a typical 1,000 to 5,000 nt mRNA is in the 300 to 1,500 kDa range, depending on length and base composition.

Forensic DNA quantification. Real-time PCR against human-specific targets (e.g. ALU repeats, amelogenin) uses standard curves calibrated in copies per microlitre. Converting from mass concentration to copy number requires the molecular weight of the amplicon.

Teaching and laboratory training. A molecular weight calculator is a standard aid in undergraduate biochemistry and molecular biology courses. The same calculation underlies questions about primer dilution, mass-to-mole conversion, copy-number estimation, and absorbance-based quantification.

Common Mistakes

Confusing single-stranded and double-stranded molecular weight. A common error is to use the ssDNA MW as if it were the dsDNA MW. The dsDNA MW is approximately twice the ssDNA MW for a balanced sequence, for a 1,000 bp amplicon, the ssDNA mass of one strand is roughly 330 kDa and the dsDNA mass is roughly 660 kDa. Mixing these up by a factor of two is one of the most common bench errors.

Forgetting the water correction. Adding residue masses without subtracting (n − 1) waters overestimates the mass by 18 Da per nucleotide. For a 20-mer primer that is a 342 Da error, which is small but matters for accurate molar quantification. For a 1,000 nt fragment the cumulative error is 17,997 Da (≈ 18 kDa), which is large enough to throw off a copy-number calculation.

Using the average "660 Da per bp" rule for unbalanced sequences. The 660 Da/bp average is only accurate to roughly ±5 % across typical compositions. AT-rich sequences run 1 to 3 % below average; GC-rich sequences run 1 to 3 % above. For precise work, sum the residue masses explicitly.

Confusing bases and base pairs. "Per base" and "per base pair" differ by a factor of two for dsDNA. A primer of 20 bases is 20 nt long and has the mass of 20 residues. The same primer, when hybridised to its complement, contributes 20 base pairs to the amplicon. The amplicon's molecular weight is the sum of both strands' ssDNA masses, not the mass of the primer alone.

Using Tm rules outside their valid range. The Wallace rule is a teaching-grade approximation that overestimates Tm for sequences longer than about 14 nt. A 25-mer with 50 % GC has a Wallace Tm around 100 °C, which is impossibly high; the Marmur rule gives a more realistic value around 75 °C, and the SantaLucia 1998 nearest-neighbour formula gives a salt-concentration-corrected value that can differ by 5 to 10 °C from the Marmur approximation. Always pair a Tm rule with its valid range.

Ignoring salt concentration. Tm depends strongly on [Na⁺] (and on Mg²⁺, which is present in most PCR buffers). A 25-mer measured in 50 mM Na⁺ has a Tm several degrees lower than the same oligo measured in 1 M Na⁺. The Marmur approximation assumes 1 M salt; PCR conditions are typically closer to 50 to 100 mM monovalent cation plus 1.5 to 2 mM Mg²⁺.

Misidentifying the absorbance constant. 1 OD₂₆₀ is approximately 33 µg/mL for dsDNA, 40 µg/mL for ssDNA, 40 µg/mL for ssRNA, and roughly 50 µg/mL for some RNA preparations. Using the wrong constant introduces a 20 to 50 % error in the mass calculation. Purity affects the constant too: a preparation contaminated with phenol, protein, or carbohydrate will read high at 260 nm and underestimate the actual nucleic acid concentration.

Confusing g/mol with µg/µL or ng/µL. Many spectrophotometers report concentration in ng/µL or µg/mL. The molecular weight is needed to convert that to molarity. A primer at 1 µg/µL with MW 6,000 g/mol is at 1,000 / 6,000 = 0.167 µM = 167 nM, not 1 µM.

Forgetting to handle ambiguous bases. Real sequences sometimes contain Ns, R/Y/K/M/S/W/B/D/H/V ambiguity codes, or non-ACGT characters. The calculator excludes ambiguous bases from the MW sum and from the GC/AT denominator, but flags the count in the result panel so the user knows the answer is incomplete. For an exact result, replace every N with the correct nucleotide before calculating.

Treating the calculator's result as authoritative for regulated work. The calculator implements the standard textbook formulas and is appropriate for education, planning, and routine bench work. For clinical diagnostics, regulatory submissions, or any application where the result will appear in a published study, verify against a domain expert or a regulated calculator (e.g. IDT OligoAnalyzer, NEB Tm calculator, ExPASy ProtParam).

Frequently Asked Questions

What is the molecular weight of a single nucleotide?

The four standard deoxynucleotide monophosphates (dNMPs) have these canonical molecular weights: dAMP = 313.21, dTMP = 304.20, dGMP = 329.21, dCMP = 289.18 g/mol. The average across all four is roughly 309 g/mol per nucleotide. For RNA the equivalent rNMPs are heavier: AMP = 347.22, UMP = 306.17, GMP = 363.20, CMP = 323.20 g/mol (average ≈ 335 g/mol). These values include the phosphate, the deoxyribose (or ribose), and the nitrogenous base, they are the residue masses used in polymerisation, not the masses of the free nucleotides (which carry an extra OH on the phosphate).

What is the average molecular weight of a base pair?

The widely cited rule of thumb is 660 Da per base pair for dsDNA, with a simplified "650 Da per bp" approximation that assumes average salt and base composition. The exact value depends on the A-T vs G-C ratio: AT-rich sequences run around 635 to 650 Da/bp and GC-rich sequences around 665 to 680 Da/bp because G·C base pairs have one extra hydrogen bond but only marginally different mass. For a balanced sequence with 50 % GC, the per-base-pair average is around 660 Da; for a 70 % GC sequence it can rise to 670 Da or higher. The calculator returns the exact value for the input sequence rather than an approximation.

How accurate is the "660 per base pair" rule?

Accurate to roughly ±5 % for typical sequences with 40 to 60 % GC content. AT-rich sequences are slightly lighter (around 635 Da/bp) and GC-rich sequences slightly heavier (around 665 to 680 Da/bp). The rule is exact only when the average base composition is balanced. For a 1,000 bp fragment at 50 % GC the rule gives 660,000 Da; the calculator's exact value, summing all 1,000 residues explicitly and subtracting 999 waters per strand plus the 2,000 waters for the helix termini, will fall within a few percent of that.

Why is DNA quantification usually done at 260 nm?

The aromatic nitrogenous bases (especially the purines adenine and guanine and the pyrimidines cytosine, thymine, and uracil) absorb strongly at 260 nm because of the conjugated ring systems in their structures. Each base has a different molar extinction coefficient, but the average absorption per nucleotide is similar enough across A, C, G, T (and U) that a single conversion factor works for routine quantification. The standard factors, 1 OD₂₆₀ ≈ 33 µg/mL for dsDNA, 40 µg/mL for ssDNA / ssRNA, and 50 µg/mL for some RNA preparations, are what every spectrophotometer, NanoDrop, and Qubit fluorometer uses as its baseline. Purity is typically assessed by the A₂₆₀/A₂₈₀ ratio (≈ 1.8 for pure dsDNA, ≈ 2.0 for pure RNA) and the A₂₆₀/A₂₃₀ ratio (≈ 2.0 to 2.2 for clean nucleic acid).

What is the difference between ssDNA and dsDNA molecular weight?

For a sequence of n nucleotides, dsDNA MW is approximately 2 × ssDNA MW. The exact dsDNA mass for a sequence given as one strand is 2 × ssDNA mass minus 2 × 18.015 (one water lost at each helix terminus). For a balanced sequence this collapses to the "660 Da per bp" rule. For unbalanced sequences the per-base-pair mass varies, but the relationship 2 × ssDNA mass ≈ dsDNA mass holds to within a few percent.

How do I calculate the mass of a primer from a measured absorbance?

Divide the mass concentration (µg/mL, derived from OD₂₆₀ × 40 for ssDNA) by the molecular weight (g/mol) and multiply by 10⁶ to get nanomoles per millilitre. Concretely, a primer at 1 OD₂₆₀ in a 1 mL cuvette is at 40 µg/mL. For a 20-mer with MW ≈ 6,000 g/mol, that is 40 / 6,000 × 10³ nmol/mL ≈ 6.67 nmol in the 1 mL volume. To make a 100 µM stock, dilute 6.67 nmol / 100 µM / 1 mL × 10³ = 66.7 µL into the final volume, then bring the volume up to 1 mL. Most bench calculators and online tools automate this calculation, but the underlying formula is just nmol = mass / MW.

What is the molecular weight of an RNA molecule?

RNA uses uracil (UMP = 306.17 g/mol) instead of thymine (TMP = 304.20 g/mol) and carries a 2'-OH on the ribose that DNA lacks. RNA nucleotides are therefore slightly heavier than DNA on average: ≈ 335 g/mol per nucleotide (AMP 347.22, UMP 306.17, GMP 363.20, CMP 323.20). A 1,000 nt mRNA molecule therefore has a molecular weight of roughly 335,000 g/mol (≈ 335 kDa) before any base modifications, capping, or poly-A tail. With a 5′ cap (≈ 325 Da) and a poly-A tail of 100 nt (≈ 33,500 Da), a 1,000 nt mRNA weighs about 369 kDa total. The calculator's RNA mode uses these rNMP masses and treats T as U so the same formula applies.

What is the difference between the Wallace rule and the SantaLucia 1998 Tm formula?

The Wallace rule (also called the 2 + 4 rule) is the simplest Tm approximation and treats each base pair as contributing a fixed amount: 2 °C per A·T pair and 4 °C per G·C pair. It is exact for very short oligos (≤ 14 nt) and roughly equimolar salt, but overestimates Tm for longer sequences because it ignores nearest-neighbour effects. The SantaLucia 1998 unified nearest-neighbour parameters (SantaLucia, PNAS 95:1460 to 1465) are the modern standard for accurate Tm prediction on oligos of any length, at any monovalent cation concentration, and with optional corrections for Mg²⁺, DMSO, and other PCR cosolvents. For most routine work the Wallace rule (≤ 14 nt) and the Marmur approximation (> 14 nt) are sufficient; for designing qPCR probes and matching primer Tm to within a few degrees, the SantaLucia parameters are worth the extra complexity.

Why does the calculator ask for an RNA mode toggle?

The standard deoxynucleotide masses (dAMP, dTMP, dGMP, dCMP) and the standard ribonucleotide masses (AMP, UMP, GMP, CMP) differ because of the 2'-OH group on ribose and the different mass of uracil vs thymine. Forgetting to switch to RNA mode for an RNA sequence introduces a systematic error of roughly 7 to 8 % per nucleotide (because the average rNMP is ≈ 335 g/mol vs ≈ 309 g/mol for dNMP). The toggle lets the same tool handle oligos, mRNA, gRNA, siRNA, and other RNA species without writing a separate calculator. In RNA mode, any T in the input is treated as U (the same mass, 306.17 g/mol) so sequences typed in DNA style still work.

Can I use this calculator for commercial or clinical work?

The formulas implemented here are the standard textbook values used in molecular biology for the last several decades. They are appropriate for routine bench work, primer design, oligonucleotide ordering, teaching, and any application where a small (≈ 5 %) approximation error is acceptable. For clinical diagnostics, regulatory submissions, forensic casework, or any application where the molecular weight will appear in a published paper or a regulated protocol, verify the result against a domain expert, a regulated calculator, or the IDT OligoAnalyzer / NEB Tm calculator / ExPASy ProtParam web tools. The calculator does not adjust for salt concentration, Mg²⁺, DMSO, or other PCR cosolvents in its Tm calculation, and assumes standard bench conditions for the absorbance conversion.

How long does the calculator take to run?

The calculation is closed-form (a sum over nucleotides plus a few algebraic operations), so the runtime is effectively instantaneous even for sequences of thousands of nucleotides. A 10,000 nt fragment takes roughly the same time as a 10 nt fragment, well under one millisecond on any modern browser. There is no random sampling, no iterative method, no machine-learning model whose behaviour might drift between versions. The same inputs always produce the same outputs.

What input size is supported?

The calculator accepts sequences up to roughly 100,000 nucleotides and rejects anything larger with a clear error message. For longer sequences (whole plasmid sequences, viral genomes, bacterial chromosomes), the calculator's exact sum is correct but the result panel becomes hard to read. For typical primer, probe, adapter, gRNA, and short-amplicon sequences (the most common use cases), the calculator is well within its design range.

References

• Sambrook, J. & Russell, D. W. Molecular Cloning: A Laboratory Manual, 3rd ed., Cold Spring Harbor Laboratory Press. (Standard reference for nucleic acid quantification and the water-correction formula.)
• SantaLucia, J. (1998) "A unified view of polymer, dumbbell, and oligonucleotide DNA nearest-neighbor thermodynamics", PNAS 95:1460 to 1465. (Foundational paper for nearest-neighbour Tm parameters.)
• Thein, S. L. & Wallace, R. B. (1986) "The use of synthetic oligonucleotides as specific hybridization probes in the diagnosis of genetic disorders", in Human Genetic Diseases: A Practical Approach, IRL Press. (Wallace rule origin.)
• Marmur, J. & Doty, P. (1962) "Determination of the base composition of deoxyribonucleic acid from its thermal denaturation temperature", J. Mol. Biol. 5:109 to 118. (Marmur Tm approximation origin.)
• IDT (Integrated DNA Technologies) OligoAnalyzer web tool, oligonucleotide property calculator used as a cross-check for residue masses and Tm values.
• Sigma-Aldrich technical bulletin "Oligonucleotide Properties", DNA and RNA residue masses and 260 nm absorbance conventions.
• Thermo Fisher Scientific "Spectrophotometric quantification of nucleic acids", extinction coefficients and conversion factors at 260 nm.
• ExPASy ProtParam (Swiss Institute of Bioinformatics), protein and peptide molecular weight reference; the water-correction convention used here is the same.
• NCBI genetic code translation table 1, for cross-reference on the standard DNA / RNA alphabets.
• Watson, J. D. et al. Molecular Biology of the Gene, 7th ed., Pearson, standard textbook treatment of nucleic acid chemistry, base composition, and Tm.
• CRC Handbook of Chemistry and Physics, 102nd ed., Section 7: Biochemistry, reference values for nucleotide masses and physical constants.