Before attempting the literature search it is useful to identify key components of the research question. Questions to ask might be:

• What is the intervention/exposure/procedure*?
• What animal is being considered?
• What is the disease/health problem being addressed?
• What is the outcome of interest?

There is no single simple method to identify the 3Rs in the literature. The researcher has to use their own background knowledge to try to identify places in the protocol where the 3Rs might be applicable. 

*For routine procedures visit the Animal Welfare Information Center webpage on the topic. 

Search Example: Intranerve injection with a mouse model.

We will build a search for each concept using this basic search method:

Procedure AND Animal Used 

Procedure Search String:

We can build a search for "intranerve injection" with the following string of synonyms: 

("intranerve injection" OR "nerve injection") 

• You must enclose the synonym string in parentheses () in order for the string to be treated as a single unit in PubMed.
• Enclosing multi-word phrases in quotes " " forces PubMed to find the words together as an exact phrase.  

Animal Search String:

Next we focus on the animal used, in this case a mouse.

(mouse OR mice OR "mus musculus")

Combine the two with AND:

Preserving the parenthesis and the quotation marks simply join the two search strings wtih the boolean operator AND.

("intranerve injection" OR "nerve injection") AND (mouse OR mice OR "mus musculus")

Managing the Results:

Copying and pasting the search into the PubMed yields 12 results.

Remember to make sure your search results are always sorted by "Best Match" or "Relevance". This is especially useful if you have a large number of results.  

• Create your literature search in a Word Document

  • Simply copy and paste the search from Word into PubMed. This way you will have a documented search strategy for your IACUC protocol.

• Capitalization does not matter in database searching
• A dash — is treated as a blank space in PubMed. intra-nerve = intra nerve 
• Boolean operators can be lower or upper case in PubMed: AND, OR, NOT = and, or, not