The dose–response relationship, or exposure–response relationship, describes the change in effect on an organism caused by differing levels of exposure (or doses) to a stressor (usually a chemical) after a certain exposure time, or to a food. This may apply to individuals (e.g., the dose makes the poison: a small amount has no significant effect, a large amount is fatal), or to populations (e.g.: how many people or organisms are affected at different levels of exposure).
Studying dose response, and developing dose–response models, is central to determining "safe", "hazardous" and (where relevant) beneficial levels and dosages for drugs, pollutants, foods, and other substances to which humans or other organisms are exposed. These conclusions are often the basis for public policy.
The U.S. Environmental Protection Agency has developed extensive guidance and reports on dose-response modeling and assessment, as well as software. The U.S. Food and Drug Administration also has guidance to elucidate dose-response relationships during drug development.
A dose–response curve is a simple X–Y graph relating the magnitude of a stressor (e.g. concentration of a pollutant, amount of a drug, temperature, intensity of radiation) to the response of the receptor (e.g. organism or population under study). The response may be a physiological or biochemical response, or even death (mortality), and thus can be counts (or proportion, e.g., mortality rate), ordered descriptive categories (e.g., severity of a lesion), or continuous measurements (e.g., blood pressure). A number of effects (or endpoints) can be studied, often at different organizational levels (e.g., population, whole animal, tissue, cell).
Labii has developed widgets to perform dose-response relationship analysis:
Dose Response 96-Well
Perform dose-response relationship analysis
This widget can:
Design layout based on 96-well plate
Transform (normalize) the data with provided formula
Perform dose response curve fit
Calculate EC50/IC50, min, max, hill slope
Draw dose response curve
Click the LABEL tab to navigate to 96-well layout for labels. You can customize the compound, control and dose at this tab.
Labels goes to first row and first column. Specifically, does label goes to the first row.
The label and value of control is optional. The control label can be defined during the analysis.
You do not need to use all wells. The blank wells will be block out.
Click the VALUE tab to switch to 96-well layout for values. You can upload the values in this tab.
Click the ANALYSIS button to prepare the analysis. This requires the label and value provided. Click the Submit to start analysis. It usually take a few seconds to perform the analysis.
Data Transform Formula - Use this formula to transform or normalize your data. The widget will replace your value accordingly.
VALUE - The data point
UPPER - The average value of Upper Control
LOWER - The average value of Lower Control
Label (Control) - The label of the Control. For example "Control".
Label (Upper Control) - The label of the Upper Control. For example "Upper"
Label (Lower Control) - The label of the Lower Control. For example "Lower"
Click "Add Parameters" to provide compound specific parameters.
Compound - The label of the compound. It have to be identical to the label design in the 96-well
Hill Slope - The value of hill slope you want to customize.
maxfev - The maximum number of calls to the function during the curve fit. Default to 1000, max to 10000. Increase this value when you see the error of "Reach maxfev limit.'
If the analysis is successful, you shall see a list of results.
This give you the average value of each control.
This gives you the formatted data for dose response curve fit. The data display the columns of compound, dose, response, response_transformed. Each duplicates are displayed in one row. The blocked out data point will not be included.
Data of fit
This gives the calculated value for top, bottom, hill slope, ec50 after fit.
Dose response curve
A new picture will be created and saved to your files. The created the curve file is downloadable.