How It Works
This planner works in 4 steps.
Enter the available volume
Type the sample volume on hand, minus the tube's dead volume.
Enter the dilution and test volume
Type the dilution factor and the diluted volume each test uses.
Enter replicates
Type the number of replicate tests.
Read the fit check
The planner returns sample needed, fit or short, and the maximum replicates the sample supports.
The Formula
The formula divides the total diluted volume needed by the dilution factor and compares the result with the available sample.
V_need = V_test × r / DFV_need ≤ V_availr_max = ⌊V_avail × DF / V_test⌋- V_test:
- Diluted volume per test
- r:
- Replicates
- DF:
- Dilution factor
- V_avail:
- Available sample volume
20 µL of serum at 1:100 with 2 tests of 200 µL each needs 4 µL of sample. The sample supports up to 10 tests.
Conversion Table
The conversion table checks 5 test plans against the available sample volume.
| Available sample | Dilution | Tests | Sample needed | Result | Max tests |
|---|---|---|---|---|---|
| 50 µL | 1:10 | 100 µL × 3 | 30 µL | Fits | 5 |
| 20 µL | 1:100 | 200 µL × 2 | 4 µL | Fits | 10 |
| 10 µL | 1:5 | 50 µL × 4 | 40 µL | Short | 1 |
| 5 µL | 1:50 | 100 µL × 2 | 4 µL | Fits | 2 |
| 100 µL | 1:2 | 200 µL × 3 | 300 µL | Short | 1 |
What Is the Sample-Limited Dilution Planner?
The Sample-Limited Dilution Planner is a tool that fits a dilution scheme within a fixed, small sample volume and returns how many tests, replicates, or dilution levels that volume supports. The planner works backward from the sample on hand.
Patient samples, rare cell lysates, and archived extracts often come in 5 to 50 µL amounts. The planner sums the sample consumed by every dilution and replicate, compares it with the available volume, and suggests changes, such as higher dilution factors or fewer replicates, when the sample falls short.
Common Uses
There are 5 main uses of this planner.
Pediatric and small-volume samples
Clinical labs plan tests within small draws.
Biobank requests
Researchers plan assays within approved aliquot volumes.
Rare cell lysates
Users fit several assays into one lysate.
Archived extracts
Labs plan reanalysis within remaining volume.
Add-on tests
Clinical staff check whether a sample supports another test.