Calculator Inputs
Example Data Table
| Sample | Replicates | Dilution | Assay Volume (mL) | Elution Volume (mL) | Original Volume (mL) | Recovery (%) |
|---|---|---|---|---|---|---|
| Sample A | 145, 151, 148 | 10^-5 | 0.10 | 2.00 | 50.00 | 82 |
| Sample B | 92, 95, 97 | 10^-4 | 0.20 | 1.50 | 25.00 | 76 |
| Sample C | 210, 205, 198 | 10^-6 | 0.10 | 3.00 | 100.00 | 88 |
Formula Used
Mean = (sum of replicate measurements) / (number of replicates)
Raw concentration = (mean count × dilution denominator) / measured assay volume
Original concentration = raw concentration × (elution volume / original sample volume) ÷ recovery fraction × conversion factor
Total load = original concentration × original sample volume. Expanded uncertainty is estimated here as two times the replicate CV for quick screening.
How to Use This Calculator
- Enter a report label so exported files are easier to recognize.
- Choose the unit that matches your already obtained measurement output.
- Paste replicate values into the replicate box using commas, spaces, or semicolons.
- Enter the dilution denominator. For a 10^-5 dilution, use 100000.
- Provide the measured assay volume, elution volume, original sample volume, and recovery efficiency.
- Use the conversion factor only when you need to scale results to another equivalent reporting basis.
- Select Calculate Viral Concentration to display the result panel above the form.
- Use the CSV or PDF buttons to export the calculated summary for documentation.
Frequently Asked Questions
1. What does the dilution denominator represent?
It is the inverse of the dilution written as a whole number. A dilution of 10^-5 becomes 100000. The calculator multiplies the observed mean by this number before dividing by assay volume.
2. Why are replicate values entered together?
Grouped replicates let the calculator compute a mean, spread, and coefficient of variation. That helps you judge whether the measurements are consistent enough for reporting or whether another review is needed.
3. What is recovery efficiency doing in the result?
Recovery efficiency adjusts the measured concentration upward when the measured workflow captures only part of the material. Lower recovery percentages lead to higher back-calculated original concentrations.
4. When should I change the conversion factor?
Leave it at 1 unless you intentionally need extra scaling between equivalent reporting bases. It is useful when your workflow requires a final multiplier beyond dilution, volume, and recovery adjustments.
5. Does the calculator estimate uncertainty?
Yes. It uses replicate variability as a quick screening estimate. The displayed expanded uncertainty is two times the replicate coefficient of variation, which is useful for simple internal comparisons.
6. Can I use copies, particles, and PFU units?
Yes. The dropdown changes the displayed reporting label only. The underlying math is the same, so you should select the unit that matches your measurement source.
7. Why is the result shown above the form?
This layout keeps the answer near the top of the page after submission, making it easier to review export options and summary metrics without scrolling back upward.
8. Is this calculator a laboratory procedure guide?
No. It is a data-analysis tool for already obtained measurements. It does not provide laboratory steps, growth conditions, handling methods, or optimization advice for biological materials.