Save yourself some time! Use subject headings or MeSH
One strategy that can make your research run more smoothly is the use of subject headings, like Medical Subject Headings (MeSH). Subject headings are what we call "controlled vocabulary." In other words, they are terminology that are used to identify all the articles on a given topic. For example, you could do one search for articles with the subject heading "Carbonated Beverages," instead of searching for all variations of the word "pop" (i.e. "soda," "coke," "soft drink").
Most databases make their own brand of subject headings; PubMed uses "MeSH" (Medical Subject Headings), but CINAHL uses "CINAHL headings". They still work the same.
The Clinical Laboratory Techniques branch of the MeSH tree.
There are many Medical Subject Headings which refer specifically to Clinical Laboratory Techniques, both within the context of Diagnosis, as well as Investigative Techniques. Try adding these MeSH terms to your search in order to find articles written from a Medical Lab Science perspective. Note the format; this must be maintained in order for the database to recognize the subject headings.
Diagnosis branch of the MeSH tree:
Investigative Techniques branch of the MeSH tree: