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Research Guides@Tufts

General Genetics

General Genetics

Genetic disease, conceptual computer artwork. Five chromosomes each with one of their genes highlighted (red).

Laguna Design / Science Photo Library / Universal Images Group

Genetic Disease. [Photography]. Retrieved from Encyclopædia Britannica ImageQuest.

Primary and Secondary Literature

Primary Literature

  • Primary literature presents results of original research in formats such as articles, pre-publication prints of articles, and conference proceedings. Of the sources in this category, you are most likely to find and use journal articles, whether traditional paper journals or those you will find online.
  • When you see the word "article," don't assume that you will be consulting Time or Rolling Stone to find primary materials. True, those publications carry many articles, but the type you want will be found in scholarly and academic journals like Nature and Science. These articles contain original data and have been "peer-reviewed" by scientists familiar with the area being researched.
  • The most efficient way to find primary literature is by using indexes and databases. These allow you to search journal literature by author, subjects, or keywords and find citations to relevant articles. A citation includes the author and title of an article, the title of the periodical in which it was published, page numbers, date of publication, and other information. Some citations provide abstracts (summaries) of the cited article. The citation gives you all the information you need to find the journal that contains the article in the Tisch Library.
  • Primary literature is usually peer reviewed or refereed.


Dewar, William K. Oceanography: A fishy mix. Nature 460, 581-582 (30 July 2009) | doi:10.1038/460581a; Published online 29 July 2009


Secondary Literature

  • Secondary literature includes books, annual reviews, textbooks, and some periodicals. These sources differ from reference materials in at least one important way: secondary sources, like reference materials, may answer factual questions; however, they also present background information and summarize results of scientific work so that you can read the full range of thinking on a particular topic. Secondary literature does not present the most current scientific information, which is found in primary literature.
  • Articles in science periodicals such as Discover and Science News are considered secondary literature because they don't present the results of original research, instead such articles synthesize and summarize descriptions of previous scientific work--which makes secondary literature very useful for you.
  • Use annual reviews, textbooks, review articles in science periodicals, and books on scientific topics to gain detailed knowledge of a field, to learn about the historical development of a concept, and to become familiar with major researchers in an area of science.
  • You can find more secondary sources by using the Tufts Online Catalog, finding a relevant source, and then browsing the book stacks in the call number area where you located the first relevant source. Bibliographies in reference materials may also point you to secondary sources.


Trujillo, Alan P. Essentials of oceanography. Upper Saddle River, N.J. : Pearson Education, 2008.

Huybers, Peter and Wunsch, Carl. Paleophysical Oceanography with an Emphasis on Transport Rates. Annual Review of Marine Science 2, (January 2010).


Keyword Searching

Keyword Search Rules for the Library Catalog and Databases

Using AND/OR/NOT (Boolean Search Operators)

Use AND to focus search and combine different aspects of your topic.

Example: cofactors and ligase


Use OR to expand your search and find synonyms/related terms.

Example: ("pET vectors or "expression vectors")


Use NOT to exclude a word or phrase from your search

Example: "reaction conditions" not "reaction path"

Additional Search Tips

  • "Phrase search"  - Use quotation marks " " to search for a particular phrase.
    Example: "recombinant expression"
  • Truncation * - Use an asterisk to find variations of a word. Put an asterisk after the root of the word to find all variations of that word, including singular and plural.
    Example: enzym* (finds enzyme, enzymatic, etc.)
  • (Grouping/Nesting Keywords) - Use parentheses ( ) as a way to organize and group your search terms in a way that works with Boolean operators.
    Example: (misfolding or refolding) and "beta-galactosidase".

Cited Reference Searching

  • Cited references are found in the bibliographies or works cited sections of a journal article, book or report.
  • Cited references can be journal articles, books, reports, white papers, newspaper articles, etc.
  • This type of search strategy is useful for locating current articles or research on a topic or identifying top researchers in a field.
  • Some of the databases we subscribe to that feature this search startegy are: Web of Science, Scopus, Science Direct, CSA, Chemical Abstracts, JSTOR, Environment Complete and Google Scholar.
  • To learn more about cited reference searching go to