It was a great evening and LD50 gave a great set using equipment that we (as Dieter Muh) had once used. Minimal lethal doses were estimated from the literature and computed by assuming the victim would be a healthy male, 35 years of age weighing 150 pounds. Median Lethal Dose Definition. 半数致死量（はんすうちしりょう、median lethal dose）とは、物質の急性毒性の指標、致死量の一種としてしばしば使われる数値で、投与した動物の半数が死亡する用量をいう。"Lethal Dose, 50%"を略してLD 50 と書く。 概要 The median lethal dose, or LD50, is a term used in toxicology as a measurement of a lethal dose of a substance (e.g., pathogen, medication, toxic substance, etc.). The Lethal Dose 50 Test Procedure. LD stands for lethal dose and LD50 signifies the single dose needed to kill 50% of the animals used in the experiment. One of the most commonly quoted figures when discussing the toxicity of chemicals is the LD50, which stands for ‘lethal dose 50%’, or ‘median lethal dose.’ This is the amount of a chemical required to cause death in 50% of the animals in the group it is tested on. LD 50 is identical in definition to TD 50, except the toxic effect is death. In toxicology, the median lethal dose, LD 50 (abbreviation for "lethal dose, 50%"), LC 50 (lethal concentration, 50%) or LCt 50 is a measure of the lethal dose of a toxin, radiation, or pathogen. I first came across them in 1998 when we shared billing at the 11th International Independent Music & Arts Festival in Sint-Niklaas, Belgium. If there is one area where many scientists and animal rights campaigners are united it is in their condemnation of the LD50 test. When any ingestion is accompanied by ETOH (ethyl alcohol), it increases the toxicity level by approx 50%. LD50: The average amount of a drug, toxin, chemical substance/mixture or microorganism capable of killing 1/2 of the test animals exposed under specific test conditions. Specifically, the LD50 represents the dose at which a substance is lethal for 50… I like LD50, or Lethal Dose 50 as they are called here. Median lethal dose (LD50) is commonly expressed in mg/kg, by oral intake or skin exposure. The 14th edition of Katzung does not define it much beyond this level, nor does Neubig et al (2003), probably because it would be pointless to do so. This yields a conservative estimate since the amounts listed would be more toxic in all other people, except for heavier males. Predictably, this is the dose required to kill 50% of a test subject population. The value of LD 50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. Median lethal dose, LD 50.