radioimmunoassay vs immunoassay

radioimmunoassay and immunoassay both are nouns.

Word	Noun	Adjective	Verb	Adverb
radioimmunoassay	Yes	No	No	No
immunoassay	Yes	No	No	No

As nouns, immunoassay is a hypernym of radioimmunoassay; that is, immunoassay is a word with a broader meaning than radioimmunoassay:

radioimmunoassay: immunoassay of a substance that has been radioactively labeled
immunoassay: identification of a substance (especially a protein) by its action as an antigen

Other hypernyms of radioimmunoassay include immunochemical assay.

radioimmunoassay (noun)	immunoassay (noun)
immunoassay of a substance that has been radioactively labeled	identification of a substance (especially a protein) by its action as an antigen