Dose Response Analysis¶
Creating a Dose Response Plot¶
Howto
- Enter the dosages for each FCS file: on the annotation page, create a new column. The column can be named whatever you prefer (e.g. “dosage”).
- Type/paste/import the dosages. See dose response units for information on the format of these values.
- Create an illustration and insert a dose response chart using the button in the toolbar.
- In the right sidebar, select the name of the annotation created in step 1, then select the dosage values to display.
- Select the data series. For example, these could be different signaling readouts or different cell populations that reflect on- and off-target effects.
- Select the statistic and, if applicable, channel to fit. For example, you could select a signaling marker and “median” to look at signaling activation or inhibition; or event count/percent if looking at changes in population frequencies.
- If necessary, select the population to display.
CellEngine will fit your data using the Levenberg-Marquardt method to the Hill equation:
$$ min + \frac{max - min}{1 + 10^{(logIC50 - x)} \times hill} $$
To view the model fit parameters, including EC/IC50 values, hover over a series in the legend.
To export a table of values, including χ2, R2, and EC/IC50 values:
Howto
- In the right sidebar, under Export, click download dose response fit.
Tip
At least four dosages are required to fit a curve. Because the Hill equation calculates the log-IC50, all dosages must be greater than zero.
Dose Response Units¶
CellEngine automatically parses numerical dosages and a variety of unit types, spellings, abbreviations and SI prefixes, including:
- molar concentrations (e.g. “1 molar”, “2.5 nM”, “1 mole/liter”, “5 nanomole/millilitre”)
- mass-per-volume (e.g. “1 ug/ml”, “2 µg/milliliter”)
- mass-per-mass (e.g. “1 mg/kg”)
- mass (e.g. “5 grams”, “2 g”)
- moles (e.g. “1 mmol”, “5 nmol”)
- unitless (e.g. “1.0”)
All dosages with units will be normalized to nanomolar, nanomole, nanogram, milligram/liter or milligram/kilogram for curve-fitting. Unitless dosages will be used as-is.