guaiac tincture
- noun
- /ˈɡweɪ.æk ˈtɪŋk.tʃər/
- Specialized
- The doctor used guaiac tincture to test for blood in the stool.
Examples
-
The guaiac tincture turned blue, indicating the presence of blood in the specimen.
-
The guaiac tincture reacted when protein was present in the sample.
-
A drop of guaiac tincture was added to the solution and the color change was monitored.
-
Doctors often use guaiac tincture in tests to check for hidden blood in stool samples.
-
Have you ever heard of guaiac tinctures being used in medical tests?
-
Doctors often use guaiac tincture in tests to check for hidden blood in stool samples.
-
A drop of guaiac tincture was added to the sample to detect the presence of proteins.
Surface Forms
Morphology
The phrase transparently denotes an alcoholic preparation of guaiac — a compositional noun+noun meaning derivable from 'guaiac' (the resin/wood) and 'tincture' (an alcoholic preparation). However, its specialized medical function as a reagent for detecting blood/proteins is domain-specific and not predictable from the constituents alone, so learners would only partially infer the full meaning.
Etymology
Guaiac tincture comes from the sticky resin of the guaiac tree mixed into alcohol to make a tincture. When a drop meets tiny amounts of 'blood' or 'protein' it can change color, so doctors used it as a quick 'test' for hidden blood.