What you are given
- Standards (concentration, signal): [{"x":"0","y":"0.04"},{"x":"0.25","y":"0.21"},{"x":"0.5","y":"0.39"},{"x":"1","y":"0.75"},{"x":"2","y":"1.48"}]
Formula: signal = slope x conc + intercept
Protein
How do you calculate standard curve?
Fit a linear or quadratic standard curve (Bradford, BCA, ELISA) and read unknowns. The relationship used is signal = slope x conc + intercept.
Worked example
Every number below is computed by the calculator, not typed in
The working
- Least-squares fit:
signal = slope · conc + intercept - Slope:
slope=0.722 - Intercept:
intercept=0.0325 - Goodness of fit:
r²=0.9999 - Back-solve unknowns:
conc = (signal - intercept) / slope
Fit: signal = 0.722 x conc + 0.0325 (R2 = 0.9999).
What each symbol means
- y: Signal (absorbance, RFU, counts)
- m: Slope (signal per concentration)
- x: Concentration
- b: Intercept
A printable one-page version is on the formula sheet.
Do it with your own numbers.
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