[ **up: [[Science]]** ] --- # Bioassays > A bioassay is an analytical method to determine the potency or effect of a substance by its effect on living animals or plants (*in vivo*), or on living cells or tissues (*in vitro*). A bioassay can be either quantal or quantitative, direct or indirect. If the measured response is binary, the assay is quantal; if not, it is quantitative.[^1] > A bioassay is a biochemical test to estimate the potency of a sample compound. Usually this potency can only be measured relative to a standard compound. A typical bioassay involves a stimulus (ex. drugs) applied to a subject (ex. animals, tissues, plants). The corresponding response (ex. death) of the subject is thereby triggered and measured.[^2] The ‘canary in the coal mine’ is an example of a bioassay.[^3] --- [[2025-0320. Bioassays (repeatable experiments designed to measure biological responses) are required to back up claims re. pheromone identification.|Bioassays (repeatable experiments designed to measure biological responses) are required to back up claims re. pheromone identification.]][^4] [^1]: ‘Bioassay’, *Wikipedia*, updated 11 December 2024, https://en.wikipedia.org/wiki/Bioassay. [^2]: ‘Bioassay’, *Wikipedia*, updated 11 December 2024, https://en.wikipedia.org/wiki/Bioassay. [^3]: ‘Bioassay’, *Wikipedia*, updated 11 December 2024, https://en.wikipedia.org/wiki/Bioassay. [^4]: Tristram D. Wyatt, ‘[[Wyatt. ‘Pheromones’, 2017.|Pheromones]]’, *Current Biology*, vol. 27, issue 15 (7 August 2017), p. R739.