University of Saskatchewan

September 16, 2014   

How Can I Search the Patent Literature? 


Why would a university researcher want to search the patent literature?

There is often information available in the patent literature that is not available in scientific publications.  In most countries, patents are granted on a first-to-file basis. Whoever files an application for a particular invention first will be the one granted the patent, even if they weren’t necessarily the first to come up with the idea and put it into practice.  As a result, patent applications are generally filed early in the research process, often before the research would be ready for publication in a peer-reviewed journal.  Patent applications are published 18 months after first filing and can give you a good indication of where research is headed at an early stage in the process.  This can help to better inform you about the research that is being carried out in your field and could, perhaps, suggest new areas of investigation.

If you are carrying out research in an area of commercial interest and are considering pursuing patent protection for one or more inventions that arise from your research, it is critical to know what information has already been made public.  In order for a patent application to succeed, the claimed invention must be both novel* and non-obvious.  If you don’t know what has already been published, then you run the risk of repeating the research efforts of others and investing precious resources into research that will not lead to a patentable invention.   While a search of the patent literature will not inform you about every invention for which an application has been filed (there is an 18 month delay before patent applications are made public), it is essential background research that should be carried out before starting any new commercial research endeavour.  For best results, patent literature searches should be repeated routinely as your research progresses in order to identify relevant patent applications that have been recently published.

* In order for an invention to be considered novel, it must not have been disclosed previously by anyone (including the inventor(s)), in any language, anywhere in the world, in any type of public disclosure – this includes patents, patent applications, scientific journals, conference proceedings, newspaper/magazine articles, websites, trade shows, sale of a product, etc.  With regard to patent applications, it is irrelevant whether or not the published application leads to a patent being issued.  The mere disclosure of the information is sufficient to invalidate future patent applications directed to the same invention.

A brief introduction to the anatomy of a patent document:

The main sections of a patent or patent application are as follows:

Abstract:A concise summary of the invention.
Description:The description section of the patent or patent application will contain background information and a description of the invention as envisioned by the inventor(s).  The description usually includes one or more examples (experimental data) to support the claims. 
Claims:The claims of a patent define the aspects of the invention for which the patent holder(s) have a legal monopoly for the life of the patent (usually 20 years from the filing date).  This legal monopoly gives patent holders the right to prevent others from making any product or composition, or from carrying out any use, method, or process that falls within the scope of the invention as defined by the claims. 
Drawings*: If the description of an invention can be made clearer through the use of drawings, then drawings (figures) must be included as part of the patent application and a brief description of the drawings (akin to a figure legend) will be included in the description of the patent application.
Sequence Listing*: For inventions that relate to biological material(s), the patent application may be required to include a sequence listing that provides protein and nucleic acid sequences related to the invention.  These sequences may be unique to the patent application and will not necessarily be available in any public database other than a patent sequence database.  Information on searching patent sequences is provided below.

*The drawing and sequence listing sections may be optional, depending on the nature of the application.

Note:    Anything that is disclosed in any section of a patent or patent application (or in any other type of public disclosure) may be used to invalidate the novelty or non-obviousness of future patent applications. 

How to search patent literature using search tools available to University staff and students:

The primary ways to search the patent literature are by inventor/applicant search, keyword search, classification search, chemical structure search, sequence search, and combinations thereof. 

Inventor/Applicant Search

This will allow you to search for patents or patent applications in the name of any inventor(s) or applicant(s) (e.g. university, institution, or company name).

Keyword Search

Depending on the patent database selected, you may be able to use keywords to search the title and abstract; the title, abstract, and claims; or the full text of the patent or patent application. Different databases use different wildcards and syntax for Boolean searches, so it is worthwhile to take some time to familiarize yourself with the database(s) that you are using if you intend to carry out complex searches.

Classification Search

In order to aid people who want to search for patents or patent applications in a particular field or area, every patent application is assigned one or more classification codes that relate to the subject matter of the claims and patent search databases allow you to search for patents and patent applications using these codes. The universal standard for classification is the international patent classification system (IPC), which was established and is routinely updated by the world intellectual property organization (WIPO). 

Information about the IPC can be found at:

Databases to Search Patent Literature:

esp@cenet :
This service is provided by the European Patent Office. The search is user friendly and allows searching of keywords in the title or abstract of patents and patent applications from over 80 countries (all translated into English). You can also search the full text of European patents and patent applications or of PCT (international) patents and patent applications by selecting the appropriate patent database.

The European patent office has their own classification system (ECLA), which is based on the IPC classification system, but provides more subcategories. esp@cenet allows you to search by either IPC or ECLA. For information on ECLA classification go to:

Patentscope :
This service is hosted by the World Intellectual Property Organization (WIPO) and allows you to search the full text of international (PCT) patent applications and the full text of patents and patent applications from 18 other countries.

Patent Lens :
This service allows you to search the full text of US, European, international (PCT), and Australian patents and patent applications.

Google Patents :
This service allows you to search the full text of United States patents and patent applications. While limited to patents and patent applications that have been issued or filed in the United States, it provides very user-friendly full text searching.

This database is available to university staff and students. It allows for author searching and keyword searching of full text from the European Patent Office, the US Patent Office, the World Intellectual Property Organization, and the UK Patent Office and allows searching of title/abstract from the Japanese patent office. This database is also useful for searching scientific literature. In order to do a patent search, search with your desired keywords and then select the “patent” tab at the top of the results page to view patent hits.

Databases to Search Biological Sequences

Allows you to search for sequences in European, Japanese, Korean and US patents/applications

It is possible to search the sequence listings of patents and patent applications issued or filed in the United States using the NCBI BLAST server. Go to and choose any of the Basic BLAST programs. Then, in the “Choose Search Set” box, select “Patent Sequences (pat)” or “Patented Protein Sequences (pat)” as the search database.

DNA Databank of Japan:
Allows you to search for sequences in Japanese, Korean, European, and US patents/applications.

Databases to Search Chemical Structures

Allows for chemical structure searching within patents.

SciFinder: University staff and students can carry out chemical structure searches using SciFinder. Information about how to access SciFinder can be found at:

Additional Resources

The library provides additional resources for, and information about, searching patent literature at:

(Last Updated on Oct. 4, 2011)