tooluniverse-dose-response

name

tooluniverse-dose-response

description

Dose-response / concentration-response curve fitting — IC50, EC50, Hill slope, Emax/Emin efficacy, and relative potency from paired concentration vs response data (enzyme/cell assays, drug screening, agonist/antagonist pharmacology). Fits the 4-parameter logistic (Hill sigmoidal) model. Use when you have concentrations + responses and need a potency value, to compare two compounds' potency, or to judge curve quality. NOT for image-derived dose-response (use tooluniverse-image-analysis) and NOT for survival/regression (use tooluniverse-statistical-modeling).

Dose-Response / Concentration-Response Analysis

Turn paired concentration vs response measurements into a potency (IC50/EC50), a Hill slope, an efficacy (Emax), and a quality judgment — and compare potency between compounds.

When to use this

• Enzyme inhibition / activation assays, cell viability, reporter assays, radioligand binding, agonist/antagonist pharmacology.
• You have a list of concentrations and the response at each, and want IC50/EC50 + Hill slope.
• You want to say "compound A is N-fold more potent than B."

The model is the 4-parameter logistic (4PL) / Hill sigmoidal: f(x) = Emin + (Emax − Emin) / (1 + (EC50/x)^n) — where n is the Hill slope.

Step 1 — Prepare the data (where results go wrong)

Issue	What to do
Concentration units	Pick ONE unit (µM, nM, M) and use it for every point. The IC50 comes back in that unit. Don't mix.
Log vs linear concentrations	Pass concentrations on the linear scale (e.g. 0.01, 0.1, 1, 10), not log10. The fitter logs internally.
Zero/control concentration