# What is a standard curve?

I know you may find definitions out there for standard curve.

But, how can we define it in a way that makes it more understandable and clear of what it does?

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Can you give a reference? Standard curve doesn't seem to be a mathematical notion. –  Rasmus Feb 13 '11 at 19:03

## 1 Answer

Standard curves are usually used in the field of biology to help you identify how much "stuff" (in many cases, this is the concentration of some kind of protein) you have in your samples.

Simply put, a standard curve is a plot of known x and y values. Given just y from your experiment, you should be able to determine x from the plot of known values (standard curve).

To get into a bit more detail, a standard curve for immunoassays such as ELISAs is usually fit to the 4 parameter logistic (4PL) or 5 parameter logistic (5PL) nonlinear regression model equations.

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