Free AI-Assisted

DNA & Protein Concentration Calculator

Convert OD, mass, or molar values for DNA, RNA, or protein—batch NanoDrop, no account. Built-in AI agent assistant support.

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Key facts

Key facts about DNA & Protein Concentration Calculator
FactValue
Molecule typesdsDNA, ssDNA, ssRNA, Protein
Nucleic acid inputsOD₂₆₀, ng/µL, µg/mL, nM, pmol/µL, bp / nt
Protein inputskDa, mg/mL, µM, nM, nmol, mg
Batch modePaste or upload CSV/TSV — up to 96 rows
Purity ratiosA260/A280 and optional A260/A230 with pass/warn flags
Sequence-aware ODOptional sequence paste; Exact, Generic, or Approximate badge
HistoryLast 10 calculations saved in browser
Assumptions25°C, aqueous buffer, 1 cm path length for OD
Runs in browserYes — no install
Account requiredNo

What it does

Researchers juggling vendor calculators mid-prep retype the same NanoDrop reading three times—and pick the wrong conversion direction when switching from DNA to protein. The DNA & Protein Concentration Calculator accepts any known value as the entry point and propagates every related unit instantly, on one screen, for any molecule type.

Select dsDNA, ssDNA, ssRNA, or Protein, then type or paste the value you have—OD₂₆₀, ng/µL, nM, kDa, mg/mL, or others. All related fields update live as you edit; paste a quantity with a unit suffix (e.g. "2.4 µg/mL") and the tool routes it to the correct field. For nucleic acids, enter bp / nt length or paste an optional sequence to upgrade from generic OD factors to a sequence-specific extinction coefficient—the badge shows Exact (sequence), Generic coefficient, or Approximate (ambiguous bases).

The Dilution Advisor panel returns numbered pipetting steps for your target concentration and final volume. Open the Batch tab to paste or upload a NanoDrop CSV (up to 96 rows) and get ng/µL and nM per sample. The Purity Dashboard interprets A260/A280 and optional A230 with plain-language contamination warnings. Copy All, per-field copy, Export CSV, and the History tab (last 10 sessions) keep results at the bench without tab-switching.

Why researchers use it

  • Avoid tab-switching between NEB, Promega, and EndMemo
  • Enter any unit and get all related values instantly
  • Convert dozens of NanoDrop readings in one batch paste
  • Catch contamination with plain-language purity warnings
  • See when OD uses generic versus sequence-specific coefficients
  • Copy results or restore recent calculations without retyping

Best for

  • RNA and DNA NanoDrop quantification after extraction
  • Protein mass-to-molar conversions (mg/mL to µM)
  • NGS library prep with 12–96 NanoDrop samples
  • Checking A260/A280 purity before downstream work
  • Planning a working dilution from stock concentration
  • GC-rich or AT-rich sequences where generic OD factors mislead

When to use this vs alternatives

Choose this tool when you already have OD, mass, or molar readings and need bidirectional unit conversion, batch NanoDrop paste, or purity interpretation in one session. Use the Sequence Property Calculator when mixed DNA, RNA, and protein FASTA must become one sortable property table—not when you start from NanoDrop values. Use the Serial Dilution Planner when dilution planning needs pipette rounding or 96/384-well plate maps; the built-in Dilution Advisor covers simple C₁V₁ steps only. Use the Molarity Solution Calculator when weighing powder or correcting hydrate and purity—not converting existing liquid concentrations. NEBioCalculator and Promega Biomath still fit quick single-direction checks you already trust.

What makes it different

Most vendor calculators require picking the right tab and direction before entering data—switching from µg to pmol or from DNA to protein means starting over. NEBioCalculator is trusted but siloed with no batch mode or sequence-aware OD. Promega Biomath covers core conversions but stays one-directional with fixed OD factors. MolBioTools handles sequence-level OD for oligos but skips protein and batch input.

This browser tool treats every field as both input and output on one screen for dsDNA, ssDNA, ssRNA, and protein. Paste sequence for accurate OD₂₆₀, batch up to 96 NanoDrop rows, interpret purity ratios inline, and get dilution pipetting steps—no install or account. Researchers switch when they repeat conversions sample-by-sample, get wrong molarity for GC-rich sequences without warning, or bounce between three vendor sites during one prep.

How to get started

  1. Open the workspace and stay on the Converter tab.
  2. Select dsDNA, ssDNA, ssRNA, or Protein from the molecule selector.
  3. Click any unit field (e.g. OD₂₆₀, ng/µL, nM) and enter the value you know; related fields update live.
  4. For nucleic acids, enter bp / nt or paste a sequence under Optional: paste sequence; check the coefficient badge.
  5. Use Dilution Advisor to enter Target conc. and Final volume; read the numbered pipetting steps.
  6. Click Copy All or Export CSV; open Batch Mode → to paste NanoDrop CSV, or Purity Dashboard for A260/A280 ratios.

Frequently asked questions

How do I convert OD260 to ng/µL for DNA?
Select dsDNA, ssDNA, or ssRNA, enter your OD₂₆₀ reading, and set bp / nt length. The calculator applies the standard factor for your molecule type—50 ng/µL per OD for dsDNA, 33 for ssDNA, 40 for ssRNA—at 1 cm path length. ng/µL, µg/mL, nM, and pmol/µL populate instantly. For non-average GC content, paste the sequence under Optional: paste sequence so the tool uses a sequence-specific extinction coefficient instead of the generic factor.
How do I convert ng/µL to nM for a DNA fragment?
Enter ng/µL as your anchor value and set bp / nt to the fragment length. Molarity derives from mass concentration and length using 650 Da per bp for dsDNA (340 Da per nt for ssDNA or ssRNA). All fields update bidirectionally—change nM instead and ng/µL recalculates. Values outside typical lab range trigger an inline warning so you can verify the input before pipetting.
Can I batch-convert NanoDrop readings from a CSV?
Yes. Open the Batch tab, set Default length (bp) or Default MW (kDa) for protein, then paste or Upload file a CSV or TSV with up to 96 rows. The results table shows OD₂₆₀, ng/µL, and nM per sample (or mg/mL, µM, nM, kDa for protein). Click Download CSV when all rows pass validation; rows with errors highlight in red and block export until resolved.
What does the A260/A280 ratio mean for my sample?
Open the Purity Dashboard tab, select your molecule type, and enter A₂₆₀ and A₂₈₀ (plus optional A₂₃₀). The tool computes A260/A280 and flags pass, warn, or fail against expected ranges—roughly 1.7–2.0 for dsDNA, ~2.0 for RNA, ~0.5–0.6 for pure protein. Plain-language messages explain likely contamination (protein, phenol, salt, or RNA carryover). Use this check before committing sample to PCR, sequencing, or transfection.
Why does my OD conversion differ from the generic factor?
Standard tools assume average extinction coefficients (50/33/40 ng/µL per OD). GC-rich or AT-rich sequences can be wrong by 10–30%. Paste your sequence on the Converter tab; when bases are valid, the badge shows Exact (sequence) and OD-derived concentrations use nearest-neighbor extinction. Without a sequence, Generic coefficient applies—fine for rough estimates, but verify critical preps with sequence input or an independent method.
How does the Dilution Advisor work?
After entering a stock concentration in any field, open Dilution Advisor on the Converter tab. Enter Target conc. (nM, µM, ng/µL, or mg/mL) and Final volume (µL or mL). The tool returns numbered pipetting steps—stock volume to add and buffer to bring up to final volume. For protein, enter kDa first; otherwise the panel shows Enter MW to unlock. For multi-step serial dilutions with pipette rounding or plate maps, use the Serial Dilution Planner.

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