Lethal Concentration 50
Lethal Concentration 50 - Related Videos
08:26
Measuring the 50% Haemolytic Complement (CH50) Activity of Serum
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Cited by 92 •
2010
The classical pathway is activated by antibody and culminates in target cell lysis. The CH50 assay provides a measure of the complement activity of a serum sample. This video demonstrates the steps involved in determining the CH50 of a serum sample, the calculations and interpreting of results.
14:40
Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana
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Cited by 34 •
2012
This study concerns the development and standardization of a valuable methodological protocol to determine long-term (14 days) lethal toxicity exerted by chemical substances, industrial wastewater or sewage and liquid environmental samples on the saltwater crustacean, Artemia franciscana.
02:41
Lethal Alleles
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2021
Agouti: A Lethal Allele Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
08:39
Shifting Zebrafish Lethal Skeletal Mutant Penetrance by Progeny Testing
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Cited by 8 •
2017
The goal of this protocol is to alter the penetrance of lethal skeletal mutant phenotypes in zebrafish by selective breeding. Lethal mutants cannot be grown to adulthood and bred themselves, therefore this protocol describes a method for tracking and selecting penetrance through multiple generations by progeny testing.
09:09
Lethality Bioassay Using Artemia salina L.
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Cited by 20 •
2022
This work aims to evaluate and review the Artemia salina lethality bioassay procedure, also identified as brine shrimp lethality assay. This simple and cheap method gives information about the general toxicity (considered as a preliminary toxicity evaluation) of samples, namely, natural products.
FAQs
The estimate is derived by comparing mortality observed across several exposure concentrations and identifying the concentration-response midpoint associated with 50% mortality. Researchers record outcomes over a specified exposure period, then analyze the relationship between concentration and mortality rather than relying on a single test concentration. This approach provides a comparative toxicity measure under the tested conditions.
Exposure duration defines the time window in which mortality is measured, so it is part of the result's meaning. Two tests using the same substance and organism may not be directly comparable if they use different periods. Reporting the specified duration helps researchers interpret the concentration-response relationship consistently and avoid treating values from different conditions as equivalent.
An LC50 value reflects the conditions under which organisms were exposed, including the species, life stage, exposure duration, and surrounding environmental conditions. Differences in any of these factors can change the observed mortality pattern and the resulting midpoint estimate. Careful comparison therefore requires checking whether studies used sufficiently similar biological and environmental settings.
A typical workflow begins by selecting the test organism and defining the exposure conditions. Researchers then expose groups to several concentrations of the substance, maintain exposure for a specified period, and record mortality at the relevant endpoint. Finally, they analyze the concentration-response data to estimate the concentration associated with 50% mortality.
The experiment requires a test substance, a biological population, several exposure concentrations, and a defined exposure medium such as air or water. Researchers must also specify the exposure period and relevant biological conditions, including species and life stage. These details establish the context needed to interpret the mortality data and compare results responsibly.
This testing is used to characterize hazards associated with pesticides, pollutants, pharmaceuticals, and other chemicals. The resulting estimate helps researchers organize toxicity information and evaluate how a substance affects a defined test population under controlled exposure conditions. Its value is greatest when the reported concentration, mortality period, organism, and environmental context are considered together.
LC50 results provide toxicity information that can contribute to environmental risk assessment and decisions about safer chemical use. In biological techniques, researchers can use the estimate alongside the exposure conditions and organism-specific context to characterize potential hazards. The result does not stand alone; its relevance depends on how closely the tested scenario represents the situation being evaluated.