Walkthrough: determine an unknown concentration

Get the synthetic inputs

The plate contains six paired standard levels, two independent unknown measurements, a quality control and a blank. The unknown should be about 60.5 ng/mL after its ten-fold dilution correction, and the QC about 100 ng/mL. These are example results, not customer qualification evidence.

• Download concentration example CSV
• Download concentration setup note

Load and inspect the manual example

The editor numbers standard levels from the highest concentration down; the CSV places the pairs from low to high. Inspect the concentration associated with each well rather than assuming that level 1 means the leftmost pair.

1. Open New analysis, choose Concentration determination, then Configure manually. On Import plate measurements, choose Load example assay. This loads interpolation-linear.csv and its example configuration; it does not run it.
2. Confirm the 96-well source range A1:L8. Continue to Map the plate and inspect the assignments in the table below. Leave all other wells unassigned, even though the source contains numerical zeros there.
3. Continue to Define the dilution series. Check ng/mL, the six standard concentrations and reportable standard roles, ten-fold dilution factors for Unknown 1 and Quality control 1, and expected QC concentration 100 ng/mL. Standards are technical replicates within each level; the unknown and QC are independent replicates.
4. Continue to Model. Check Linear calibration, Untransformed concentration and response, Unweighted and increasing Curve orientation. Inspect the example’s minimum calibration R-squared criterion: 0.980 at three decision decimal places. Keep the example settings and no exclusions.
5. Check the displayed reportable calibration range of 1–32 ng/mL and wait for Draft saved. This range applies to the concentration interpolated on the curve; the sample’s dilution-adjusted concentration can be larger.

Prepare the same analysis with assistance

For a useful recovery exercise, discuss the unknown without giving its dilution factor and ask what is missing. Supply the documented factor 10 when requested. Do not assume the assistant can infer sample preparation from responses alone.

1. In a Team where you can develop analyses, start a separate conversation and Send: “Determine the unknown and quality-control concentrations using linear calibration and the supplied synthetic setup.”
2. Add the downloaded interpolation-linear.csv as Assay data and concentration-context.txt as Supporting document. Confirm Concentration determination, then select Propose configuration.
3. Use the setup note to answer any questions. Inspect the saved draft against the map, units, dilution factors, replicate treatment, model and criterion above. Request Update configuration or edit manually if a setting differs; review the saved state before Run.

Run the analysis and save the report

1. Choose Run analysis. Read Analysis summary and Concentration results on the completed detail. Expect Unknown 1 approximately 60.50 ng/mL (60.49–60.51 for this unchanged example) and QC approximately 100 ng/mL, with the displayed reportability and interval information.
2. Inspect calibration evidence, standards and per-well details. The unknown responses 12.0 and 12.2 correspond to about 6.0 and 6.1 ng/mL on the calibration curve before the ten-fold correction. The reported result combines the replicate estimates before rounding, so a calculation using rounded values may differ in the last displayed digit.
3. Read the suitability result and QC recovery. Then choose Load PDF preview, inspect the saved result and use Download PDF. Reopen the file and confirm the same source, model, units and result before filing.

If the result is missing or outside the expected range

Check A1:L8, the standard-pair concentrations, B1–B2 unknown assignments and dilution factor 10. If the result is about ten times too small, inspect the dilution factor before changing the model.

A sample outside the reportable calibration range is not automatically extrapolated. Review the displayed reason and follow your procedure for dilution or repeat measurement; do not convert an unavailable concentration to zero.

The blank is recorded, but its response is not automatically subtracted from the other measurements. Keep the example’s untransformed measurements unless a justified procedure specifies otherwise.