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AAT Bioquest

TD50 Calculator

TD50 stands for "toxic dose 50%" and is similar to LD50 "median lethal dose". It is given with respect to ingestion of a substance after a specified amount of time and is the dose at which that substance kills half the members of a tested population. This value is very important in toxicology as it gives an indication of substance toxicity. The TD50 value is inversely proportional to toxicity. A substance with a lower TD50 is more toxic than one which has a higher TD50. For a database of TD50 values for common compounds, please click here.

Traditionally, the doses (x-value) are entered as a ratio of the mass of the substance divided by the mass of the test subject. This corrects for differences in test subject body mass. The responses (y-value) are typically entered as percentage of population killed (range from 0 to 100). This will yield an upward-slopping sigmoidal curve. If percentage survival is used instead, a downward-slopping sigmoidal curve will be generated.

For technical assistance on using this calculator, please contact websupport@aatbio.com.

How to use this tool

1. Paste experimental data into the box on the right. Data can be copied directly from Excel columns. Data can also be comma-separated, tab-separated or space-separated values. If entering data manually, only enter one X-Value per line.

Replicates can be graphed simultaneously. Graph will generate error bars based on the standard error of the mean (SEM). Simply paste or enter all data columns to begin. Format should be as follows:

ConcentrationResponse 1Response 2...
C1R11R21...
C2R12R22...
C3R13R23...
............

Users can graph up to three data sets on the same graph for comparison purposes. To add a new data set , press the "+" tab above the data entry area.Data sets can be renamed by double clicking the tab. Each dataset will generate a corresponding TD50 value as well as the equation for the best fit line.

2. Verify your data is accurate in the table that appears.

3. Press the "Calculate TD50" button to display results, including calculations and graph.


Data Entry

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Process data

Feedback

Have a question or a feature request about this tool? Feel free to reach out to us and let us know! We're always looking for ways to improve!

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References

This online tool may be cited as follows

MLA

"Quest Graph™ TD50 Calculator." AAT Bioquest, Inc.3 May2024https://www.aatbio.com/tools/td50-calculator.

APA

AAT Bioquest, Inc. (2024May 3). Quest Graph™ TD50 Calculator. AAT Bioquest. https://www.aatbio.com/tools/td50-calculator.
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