How It Works
This planner works in 4 steps.
Enter the stock concentration
Type the standard stock value, such as 2 mg/mL (2,000 µg/mL) BSA.
List the standard levels
Type each target level, or pick a template such as the 9-point BCA set.
Set the volume per standard
Type the volume each standard needs for replicate wells, such as 3 × 25 µL.
Read the preparation table
The planner chooses the closest higher standard as the source and returns transfer, diluent, and leftover volume.
The Formula
The formula applies C₁V₁ = C₂V₂ with the closest higher standard as C₁.
V_src = C_target × V_total / C_srcV_d = V_total − V_srcV_left = V_src,made − Σ V_taken- C_src:
- Concentration of the source vial
- C_target:
- Concentration of the new standard
- V_total:
- Volume of the new standard
- V_left:
- Volume left for the assay
Vial E (500 µg/mL) is made from 325 µL of vial C (1,000 µg/mL) plus 325 µL diluent. Vial C started at 650 µL, gave 325 µL to E, and keeps 325 µL for the assay.
Conversion Table
The conversion table reproduces the 9-vial BSA standard scheme from a 2 mg/mL stock used in the Pierce BCA test-tube protocol.
| Vial | Source and volume | Diluent | Final BSA concentration |
|---|---|---|---|
| A | 300 µL stock | 0 | 2,000 µg/mL |
| B | 375 µL stock | 125 µL | 1,500 µg/mL |
| C | 325 µL stock | 325 µL | 1,000 µg/mL |
| D | 175 µL of B | 175 µL | 750 µg/mL |
| E | 325 µL of C | 325 µL | 500 µg/mL |
| F | 325 µL of E | 325 µL | 250 µg/mL |
| G | 325 µL of F | 325 µL | 125 µg/mL |
| H | 100 µL of G | 400 µL | 25 µg/mL |
| I | 0 | 400 µL | 0 µg/mL |
What Is the Standard Curve Dilution Planner?
The Standard Curve Dilution Planner is a tool that returns the source, transfer volume, and diluent volume for every standard in a calibration curve, from a single stock. The planner supports parallel, serial, and mixed schemes, such as the 9-vial bovine serum albumin (BSA) scheme in the Thermo Fisher Pierce BCA protocol.
A standard curve converts an instrument signal into a concentration. Each standard must have a known concentration and enough volume for replicates. The planner checks that every vial holds enough volume after its transfers, and it reports the volume left for the assay.
Common Uses
There are 5 main uses of this planner.
Protein assays
Biochemists prepare BCA and Bradford standard sets from 2 mg/mL BSA.
ELISA standards
Immunologists dilute kit standards through 7 levels with enough volume for duplicates.
qPCR standard curves
Molecular labs prepare 5 to 7 log levels of plasmid or gBlock standards.
Chromatography calibration
Analysts prepare HPLC and GC calibration sets.
Kit protocol conversion
Users scale a kit's standard table for more replicates or a larger plate.