Google now allows you to create custom search engines. I used this to set up a search engine that searches in well know life sciences sites.

In most cases normal web searches work fine. But sometimes you have terms that are frequently used in other contexts, e.g. hedgehog or ada

Google’s custom search engines are based on lists of URLs (or URL patterns) of sites that should be included. I suppose that behind the scene Google runs a normal web search, but filters out sites that are not included in the list.

The initial list of sites for the life sciences search engine was based on a file that lists all sites that are referenced from a popular, well-linked life sciences database.

grep ^Server dbxref.txt | perl -lne 'print $1 if m{http://(.+?)/}' | sort | uniq

If you’d like to add any sites, let me know (you can also request to participate in this search engine via Google).