LD50 stands for "lethal dose 50%" or "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 LD50 is inversely proportional to toxicity. A substance with a lower LD50 is more toxic than one which has a higher LD50. For a database of LD50 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.
MLA | "Quest Graph™ LD50 Calculator." AAT Bioquest, Inc., 6 Oct. 2025, https://www.aatbio.com/tools/ld50-calculator. | |
APA | AAT Bioquest, Inc. (2025, October 6). Quest Graph™ LD50 Calculator. AAT Bioquest. https://www.aatbio.com/tools/ld50-calculator. | |
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