Understand the relationship
The reasoning behind the result
Conserve material before planning volumes
m = Cstock Vstock = Cfinal Vfinal
The material amount drawn from a stock is concentration multiplied by stock volume. Equal-mass loading fixes that amount; common-concentration normalization fixes both final concentration and volume, which together determine the same amount.
This calculator uses µg for amount and µL for volume, so stock concentration must be µg/µL. Numerically, 1 mg/mL equals 1 µg/µL, but the field label should still be checked against the original measurement.
Two independent feasibility checks
The calculated stock volume must fit inside the target final volume. If it does not, adding diluent cannot create the requested concentration. The stock volume must also be no greater than the material volume available.
Infeasible rows retain the required stock volume and explain the failed constraint. They do not display a negative amount of diluent as a preparation instruction.
What counts toward final volume
The reported diluent volume is the remaining volume after the stock contribution. Any buffer or additional reagent that occupies part of the final volume must be included in that remainder according to the actual protocol.
The workbench does not select a loading amount, buffer strength, reagent composition or biologically appropriate target. It reconciles the values you enter.
Follow the numbers
Load 20 µg from two different stocks
- Stock A at 2 µg/µL requires 20/2 = 10 µL; stock B at 1 µg/µL requires 20/1 = 20 µL.
- For a 20 µL final volume, A leaves 10 µL for diluent and other entered-protocol additions; B leaves zero.
- Both contain 20 µg and end at 1 µg/µL if those final volumes are achieved.
Equal loading mass does not imply equal stock volume. Check availability and final-volume constraints separately.
Quick guide
How to use this calculator
- Select equal-mass loading or a common final concentration.
- Enter the target amount or concentration and the final volume.
- Enter each stock concentration and available volume.
- Use only rows marked feasible; a negative diluent volume means dilution alone cannot achieve the target.
Calculation method
Calculation and interpretation
Turn measured stock concentrations into an explicit per-sample volume plan without inventing a concentration target.
Vstock = target mass / stock concentration; Vdiluent = Vfinal − Vstock
Worked example
Load 20 µg from two different stocks
Equal loading mass does not imply equal stock volume. Check availability and final-volume constraints separately.
Vstock = target mass / stock concentration; Vdiluent = Vfinal − Vstock
Supported inputs
Precision and limits
Measurement controls
Entered signals must have a suitable background correction and remain within the measurement system's established working range. Saturated or incompatible measurements cannot be repaired by a ratio.
Biological interpretation
A relative signal, absorbance ratio or calculated loading volume does not establish sample purity, gene expression, mechanism, statistical significance or experimental validity.
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