Dilutional Linearity

Fit your standard curve, then paste replicate OD readings for a high-concentration sample diluted across several factors, and get FDA Bioanalytical Guidance (2018) Table 1 dilutional-linearity verdicts for ligand-binding assays — %recovery within 80–120% of expected and ≤20% CV at each dilution factor.

1. Standard curve

Paste calibrator concentration + OD pairs, one per line (tab/comma/space separated). Extra columns are treated as OD replicates and averaged for the fit, e.g. 1.25, 0.44, 0.43, 0.46. The concentration column doubles as each calibrator’s nominal value for the back-calculation check below.

2. Dilution data

Enter the undiluted sample’s nominal concentration, then for each dilution factor paste the OD replicates measured at that dilution. Expected concentration at each dilution = nominal ÷ dilution factor. FDA Table 1 wants 5 replicates per dilution factor — fewer is allowed here for testing, but the report will flag it.

Dilution factorRep 1Rep 2Rep 3