autofluorescence

noun

au·​to·​fluo·​resc·​ence ˌȯ-(ˌ)tō-flu̇-ˈre-sᵊns 

-flȯ-

plural autofluorescences

: fluorescence emitted naturally by a biological substance

In ultraviolet light, the material has a yellow to silvery autofluorescence that differs from the orange autofluorescence of lipofuscin.

—Robert S. Rust and Diane Karluk, New England Journal of Medicine, 29 Aug. 2002

Spectral-imaging technologies will discriminate emissions from multiple fluorescent probes, permitting simultaneous analysis of distinct optical probes and dramatically reducing background autofluorescence.

—Harvey R. Herschman, Science, 24 Oct. 2003

autofluorescent

ˌȯ-(ˌ)tō-flu̇-ˈre-sᵊnt 

-flȯ-

adjective

Two imaging techniques confirmed that blood flow was low in these tumors, and delivery of the naturally autofluorescent anticancer drug doxorubicin was decreased compared with delivery to transplanted tumors or normal tissue.

—Peter Olson and Douglas Hanahan, Science, 12 June 2009

Word History

First Known Use

1916, in the meaning defined above

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!