BenchLineDue Diligence
Calculation Audit
BenchLine's core equations and buffer molecular weights have been reviewed against standard laboratory chemistry formulas and authoritative compound references. This page records the calculation audit trail and professional-use boundaries.
This audit supports transparency. It is not GLP/GMP validation, regulatory certification, clinical validation, or a substitute for local SOP review.
Formula Checks
| Area | Formula or model | Result | Primary source |
|---|---|---|---|
| Single-step dilution | C1 x V1 = C2 x V2 | Correct | OpenStax Chemistry 2e |
| Serial dilution concentration | Cn = C0 / factor^n | Correct | Derived from the standard dilution equation |
| Serial dilution transfer | Vtransfer = Vfinal / factor | Correct | Derived from C1V1 = C2V2 |
| Standards sequence | Cn = Chighest / factor^(n - 1) | Correct for constant-factor standards series | Derived from the standard dilution equation |
| Top standard from stock | Vstock = Chighest / Cstock x Vtop prepared | Correct when concentration units are compatible | Derived from C1V1 = C2V2 |
| Standards volume demand | Vreserve = max(minimum usable, assay demand) x (1 + overage) + dead volume | Correct for documented reserve model | BenchLine v1.1 standards-planner design audit |
| Molarity to mass | mass = molarity x volume x molecular weight | Correct | OpenStax Chemistry 2e |
| Mass to molarity | molarity = mass / molecular weight / volume | Correct | OpenStax Chemistry 2e |
| Molarity to mass concentration | mg/mL = M x molecular weight | Correct | Unit derivation: mol/L x g/mol = g/L, and 1 g/L = 1 mg/mL |
| Henderson-Hasselbalch buffer split | pH = pKa + log10(base / acid) | Correct as a conjugate acid/base approximation | Chemistry LibreTexts |
| RPM to RCF | RCF = 1.118e-5 x radiusCm x RPM^2 | Correct when radius is in cm | MSE RCF calculator |
| Temperature conversion | C = (F - 32) x 5 / 9; K = C + 273.15 | Correct | NIST |
| SI unit scaling | Decimal powers for L/mL/uL/nL, g/mg/ug/ng, M/mM/uM/nM | Correct | NIST SI prefixes |
Buffer Molecular Weight Traceability
The app's built-in buffer molecular weights are rounded values that match authoritative compound records and reagent references at ordinary laboratory precision. Hydrate forms are handled explicitly where the app offers hydrate choices.
| Component | App MW | Cross-confirmed MW | Status |
|---|---|---|---|
| Tris base | 121.14 | 121.14 | Match |
| Sodium chloride | 58.44 | 58.44 | Match |
| HEPES free acid | 238.3 | 238.31 | Matches after app rounding |
| HEPES sodium salt | 260.29 | 260.29 | Match |
| NaH2PO4 anhydrous | 119.98 | 119.98 | Match |
| NaH2PO4.H2O | 137.99 | 137.99 | Match |
| NaH2PO4.2H2O | 156.01 | 156.01 | Match |
| Na2HPO4 anhydrous | 141.96 | 141.959 | Matches after app rounding |
| Na2HPO4.2H2O | 177.99 | 177.99 | Match |
| Na2HPO4.7H2O | 268.07 | 268.07 | Match |
| Na2HPO4.12H2O | 358.14 | 358.14 | Match |
| Sodium acetate anhydrous | 82.03 | 82.03 | Match |
| Sodium acetate trihydrate | 136.08 | 136.08 | Match |
| Acetic acid | 60.05 | 60.05 | Match |
| Potassium chloride | 74.55 | 74.55 | Match |
| KH2PO4 | 136.09 | 136.086 | Matches after app rounding |
| MES free acid | 195.24 | 195.24 | Match |
| MES sodium salt | 217.22 | 217.22 | Match |
| MOPS free acid | 209.26 | 209.26 | Match |
| MOPS sodium salt | 231.24 | 231.24 | Match |
| Citric acid anhydrous | 192.12 | 192.12 | Match |
| Citric acid monohydrate | 210.14 | 210.14 | Match |
| Trisodium citrate anhydrous | 258.06 | 258.07 | Acceptable reference rounding difference |
| Trisodium citrate dihydrate | 294.10 | 294.10 | Match |
| Sodium carbonate anhydrous | 105.99 | 105.99 | Match |
| Sodium carbonate monohydrate | 124.00 | 124.00 | Match |
| Sodium carbonate decahydrate | 286.14 | 286.14 | Match |
| Sodium bicarbonate | 84.01 | 84.007 | Matches after app rounding |
| Glycine | 75.07 | 75.07 | Match |
| Sodium glycinate | 97.05 | 97.05 | Match |
| Boric acid | 61.83 | 61.83 | Match |
| Sodium borate decahydrate | 381.37 | 381.37 | Match |
Boundaries
- Percent and fold concentration units are only treated as same-unit identities.
- Molecular-weight bridging requires a user-supplied molecular weight.
- Standards plate planning is limited to 96-well plates, standards, and blanks in v1.1.
- Plate allocation detects capacity and edge-boundary failures, but the user remains responsible for confirming the layout against local SOPs and instrument requirements.
- Standards volume planning includes minimum usable volume, assay demand, overage, dead volume, and downstream transfer demand. Overage is applied to usable demand, not to dead volume.
- Pipette profiles provide practical-volume guidance only. They do not represent calibration status, uncertainty, or verified instrument performance.
- Rotor profiles store user-entered radius information. Confirm the correct radius definition and operating limits against manufacturer documentation.
- Text, PDF, JSON, and CSV exports are calculation-support outputs, not validated records, formal audit trails, ELN records, LIMS records, or regulated quality-system records.
- Buffer pKa values and pH ranges are reference values; temperature, ionic strength, reagent purity, CO2 absorption, and calibration affect measured pH.
- Polyprotic systems such as citrate are simplified to the selected pKa region and are not full speciation models.
- The app provides calculation support, not GLP/GMP batch-record validation.
Source Families
The audit used OpenStax Chemistry 2e, NIST, Chemistry LibreTexts, PubChem, USP/FCC or other compendial references, and selected manufacturer/regulator records where needed for hydrate or salt forms.