Skip Navigation
Johns Hopkins Bloomberg School of Public HealthCAAT

Animals and Alternatives in Testing: History, Science, and Ethics

Joanne Zurlo, Deborah Rudacille, and Alan M. Goldberg


  • Acute toxicity. The short-term effects of a one-time exposure to a chemical substance.
  • Alternative. In toxicity testing, three aspects of a single concept used to describe methodologies that either eliminate the need for a whole animal (replacement alternative), substantially decrease the number of whole animals used for a particular procedure (reduction alternative), or improve the design and/or efficiency of a test, thereby lessening the distress or discomfort experienced by laboratory animals (refinement alternative).
  • Assessment of exposure. An estimate of the number of people who will be exposed to a chemical, together with concentration, duration, and terms of the exposure.
  • Battery. A group of tests that measure different manifestations of toxicity in a particular organ or system.
  • Carcinogenicity. Ability of a chemical to cause or promote cancer.
  • Chemical bank. A stock of pure chemicals that is readily available to investigators for research and validation studies.
  • Chemoprotector. An agent that negates the harmful effects of another agent or process.
  • Chronic toxicity. Effects of repeated long-term exposure to a substance.
  • Cognitive. Brain function related to sense perception and understanding.
  • Culture. Growth of living cells or microorganisms in a controlled artificial environment.
  • Cytotoxicity. Manifestation of a chemical's ability to damage or kill cells.
  • Database. A computerized collection of information.
  • Dissection. To cut apart for purposes of scientific examination, usually in reference to the cutting of dead animals or humans.
  • Endpoint. In toxicology, a biologic effect that is quantifiable and indicative of a toxic process.
  • Exposure-response relationship. The association between the amount of a chemical administered and a specific toxic effect in the organism, also called dose-response relationship.
  • Etiology. The study of the cause and/or origin of a disease.
  • Fibroblasts. A connective tissue cell found throughout the body.
  • Immortalization. Conferring the ability on cells in culture to replicate indefinitely, usually by introduction of a gene into the cell's DNA.
  • Metabolite. A chemical produced in the body following the absorption and processing of a parent chemical.
  • Microtiter plates. Plastic dishes used for culturing cells that are divided into multiple compartments, so that a large number of conditions may be tested and analyzed by automated procedures.
  • Mutagenicity. Ability of a chemical to cause changes in the genetic material.
  • Peer-reviewed journals. Scientific periodicals in which manuscript submissions are reviewed by panels of experts in the field prior to acceptance for publication.
  • Perfusion. Pumping of blood or artificial media through the blood vessels of an isolated organ to nourish it.
  • Phototoxicity. The ability of sunlight to activate or enhance a substance's dermal toxicity.
  • Protocols. A schedule of scientific investigation; an experimental procedure or series of such procedures.
  • Reference laboratories. An element in the proposed framework for validation; designated sites where previously developed in vitro assays are evaluated under identical experimental conditions, using chemicals from a designated chemical bank and cells/tissues from a designated tissue bank, with test results entered in an official data bank.
  • Risk assessment. The process through which toxic effects of exposure to a chemical substance are calculated, and a decision regarding the potential uses of the substances are made.
  • Surrogate responsibility. A concept developed by Carney and Bartlett to describe the relationship between human beings and ecosystems, as well as between scientists and laboratory animals. Surrogate responsibility assumes that the human role is one of stewardship, rather than ownership, although it does recognize the right of human beings to use animals for purposes of scientific research if standards of humane care and treatment are met.
  • Teratogenicity. The ability of a chemical substance to cause malformations in a human or animal fetus.
  • Tissue slices. An in vitro technique in which tissue is cut into thin and uniform slices so that the architecture of the organ is preserved, with all cell types present. In most cases, tissue slices are viable for a few hours or, at most, a few days.
  • Toxicity testing. In vivo and in vitro experiments designed to reveal the toxic potential of a chemical or chemicals in order to determine the potential uses (or danger of use) of the substance; an aspect of risk assessment.
  • Toxicodynamics. Alterations in a biological system resulting from exposure to chemicals.
  • Toxicokinetics. The absorption, distribution, metabolism, storage, and excretion of chemicals.
  • Transfection. Introduction of a foreign gene (DNA) into a cell's genome.
  • Vivisection. Originally the surgical cutting of a living animal in scientific research; often used today as a synonym for any type of animal research or testing.