Formulation · Free Verbex lab tool
LNP Formulation Calculator (N/P Ratio)
Plan a lipid nanoparticle formulation for mRNA or other RNA. Verbex turns RNA mass, N/P ratio and lipid mol% into the amount and stock volume of every lipid, plus the ethanol and aqueous phase volumes for mixing.
LNP formulation: SM-102 LNP, luciferase mRNA
100 µg RNA at N/P 6, mixed 3:1 aqueous:ethanol (750 µL + 250 µL).
Ethanol phase
| Lipid | mol% | Amount | Mass | Stock | Volume |
|---|---|---|---|---|---|
| SM-102 (ionizable) | 50 | 1.818 µmol | 1.291 mg | 25 mg/mL | 51.65 µL |
| DSPC | 10 | 363.6 nmol | 287.3 µg | 10 mg/mL | 28.73 µL |
| Cholesterol | 38.5 | 1.4 µmol | 541.3 µg | 10 mg/mL | 54.13 µL |
| DMG-PEG2000 | 1.5 | 54.55 nmol | 136.9 µg | 10 mg/mL | 13.69 µL |
| Ethanol to volume | 101.8 µL |
Aqueous phase
| Component | Volume |
|---|---|
| RNA stock (1 mg/mL) | 100 µL |
| Acidic buffer to volume | 650 µL |
After mixing: 1 mL, RNA 100 µg/mL, 25% ethanol; total lipid in ethanol phase 14.55 mM; lipid:RNA 22.57:1 (w/w).
Formula: phosphate = RNA mass ÷ 330 g/mol per nucleotide; ionizable lipid = N/P × phosphate ÷ amines per molecule; other lipids by mol%
Check: N/P = 1.818 µmol amine ÷ 303 nmol phosphate = 6 ✓; mol% total 100 ✓
Use molecular weights from your certificates of analysis; ethanol is usually removed by dialysis after mixing.
Verbex Lab Tools · LNP formulation v1.0 · 2026-10-13 23:36 UTC · verify before use
How it is calculated
Every number shows its work.
RNA phosphate is estimated from the RNA mass and an average nucleotide molecular weight (330 g/mol by default, about 3 nmol of phosphate per µg). The ionizable lipid needed is N/P × phosphate ÷ ionizable amines per molecule.
The ionizable lipid's mol% fixes the total lipid; every other lipid follows from its mol%. Mass = moles × molecular weight, and stock volume = mass ÷ stock concentration (or moles ÷ mM).
The ethanol phase is the aqueous volume divided by the mixing ratio. Lipid stocks plus ethanol make up the ethanol phase; RNA stock plus acidic buffer make up the aqueous phase. The check line recomputes N/P from the lipid amounts.
Use it from your AI assistant
Add Verbex Lab Tools to Claude, ChatGPT or any MCP client and ask in plain words. Your agent calls the same calculation and gets this checked notebook entry back.
https://www.verbalexperiment.com/mcpTool name: lnp_formulation. Free, no account, nothing stored.