Watson-Schwartz test

Wat·son-Schwartz test

(wot'sŏn schwōrts),
A qualitative screening test for diagnosis of acute intermittent porphyria, in which Ehrlich diazo agent and saturated sodium acetate are added to the urine. A pink or red color indicates the presence of porphobilinogen or urobilinogen. Because the former indicates porphyria and the latter does not, positive results require further differential extraction with butanol and chloroform to eliminate false-positive results.

Watson-Schwartz test

[Cecil J. Watson, U.S. physician, 1901–1983; Samuel Schwartz, U.S. physician, b. 1916]
A test used in acute porphyria to differentiate porphobilinogen from urobilinogen.


Samuel, U.S. physician, 1916–.
Watson-Schwartz test - see under Watson, Cecil J


Cecil J., U.S. physician, 1901-1983.
Watson-Schwartz test - urine test using Ehrlich reagent for acute intermittent porphyria.
References in periodicals archive ?
Urine Watson-Schwartz test was positive for porphobilinogen, Urine PBG level was 24.93 mg/ day (normal 0-4), Urine ALA level was 47.28 mg/ day (normal 1-7).
Current screening tests for PBG in urine include the Watson-Schwartz test (2) and derivatives.
Thus, the Watson-Schwartz test (1) for excessive amounts of urinary porphobilinogen, recently called "hoary' by this Journal's Editor (2), although still widely used in emergencies and favored for its easy execution with just a few test tubes and some reagents, must always lead to further detailed studies.