Standard Curve
Definition
A series of known antigen concentrations run on the same ELISA plate, used to convert the OD reading for an unknown sample into a concentration value in nanograms per millilitre.
- Input
- Series of known antigen concentrations
- Plate use
- Run on the same ELISA plate as the unknown sample
- Output unit
- Nanograms per millilitre
- Function
- Converts OD reading into a concentration value
Common questions
Why must the standard curve be run on the same plate as the sample?+
Plate-to-plate variation in reagent binding, incubation, and washing can shift OD readings even for identical concentrations. Running the standards alongside the unknown on the same plate cancels out that variation so the conversion to concentration stays accurate.
What happens if a sample's OD falls outside the standard curve's range?+
A result outside the calibrated range cannot be reliably converted to a concentration. The sample is typically diluted and re-run, or reported only as above or below the curve's detection limits rather than as a specific value.
Related terms
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