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IACUC: searching for animal alternatives

A guide for finding alternatives to the use of animals in research for Penn State.

Step 1: Protocol Specific Keywords

You must search keywords that are specific to your research protocol.

  • Most of the terminology will come from the area of study and procedures proposed in the protocol. 
  • Citations retrieved should provide information on current research, alert the investigator to whether or not they are performing duplicative studies, and possibly provide information to refine experimental techniques to minimize pain and dress, reduce animal numbers, and/or define humane endpoints.


  • The proposed intervention/exposure - include any painful or distressing procedures in your protocol
  • Scientific and common names of any species or model being studied
  • Scientific and common names of any diseases or conditions being studied
  • Generic name, trade names, and CAS RN of drugs and/or chemicals being used
  • Treatments being used
  • Scientific and common terms for tissues, systems, or cell lines being studied

Step 2: Alternatives Keywords

In addition to searching for research similar to your own, you will need to look for literature that mentions alternatives involving reduction, refinement, and replacement of animals in laboratory research.

Many people make the mistake of putting the term “alternatives” in the strategy and expect to find “all” possible alternatives. Because alternatives is a complex concept involving refinement, reduction and replacement, the use of  “alternatives” as a search term is best used only in those areas of study where larger amounts of research have been conducted on alternatives, such as in toxicology or education. In other areas of research the term “alternatives” often retrieves results not related to the 3Rs.

See also suggestions from the Animal Welfare Information Center and the National Agricultural Library:

Step 3: Suggestions for keywords describing alternatives

You need to combine your protocol specific keywords with relevant terms addressing reduction and refinement.

  • adverse
  • analgesic OR analgesia OR pain reduction OR hypnotic OR sedative OR tranquilizer
  • anesthetic OR anasthetic OR anaesthetic OR anesthesia OR anaesthesia
  • animal welfare or well-being
  • animal model
  • anxiolytic
  • assay OR technique OR method OR procedure
  • biomarker OR biological marker
  • enrichment AND (behavioral OR behavioural OR environmental)
  • environmental enrichment
  • euthanasia
  • experimental OR statistical design (pilot study, variation, sample size, etc.)
  • handling OR housing OR husbandry OR caging
  • humane endpoint
  • humane handling OR humane restraint OR humane treatment
  • imaging
  • monitoring device OR telemetry device
  • non-invasive
  • pain OR stress OR distress
  • positive reinforcement OR animal training
  • postoperative OR postsurgery
  • reduce OR reduction OR refinement
  • restraint OR restrict OR immobilize
  • welfare OR pain OR stress OR distress

You need to combine your protocol specific keywords with relevant terms addressing replacement.

  • algae OR fungus OR hydra OR plant
  • animal alternatives OR animal testing alternative OR animal use alternative (useful primarily in toxicology and education)
  • artificial
  • artificial intelligence OR AI
  • bacteria OR microorganism OR protozoan OR single-celled organism
  • cadaver OR autopsy OR carcass
  • cell culture OR cell line OR cellular
  • computer AND (simulation OR application)
  • computer aided instruction OR computer assisted instruction OR CAI
  • culture AND (cell OR tissue OR organ)
  • digital imaging
  • fish OR cephalopod
  • in silico
  • insect OR invertebrate
  • interactive
  • isolated AND (cell OR tissue OR organ)
  • mannequin OR manikin
  • mathematical  AND (biology or model or simulation)
  • membrane OR organ OR organelle OR slice OR tissue 
  • (model OR modelling OR modeling) AND (animal OR cadaveric OR interactive OR mathematical OR statistical OR theoretical)
  • non-animal model
  • Organ-on-a-Chip
  • plastination OR plastination
  • replacement OR surrogate
  • simulation OR simulator OR trainer
  • software
  • structure evaluated system
  • tissue culture OR organ culture
  • tissue engineering
  • three-dimensional OR 3D OR 3-D AND (image OR images OR imaging)
  • train OR educate OR teach OR instruct
  • video
  • virtual AND (surgery OR reality)
  • vitro AND (method OR model OR technique)