The presence of porphobilinogen in the urine can be suspected when:
A) Acidic urine turns a port wine color after standing
B) Alkaline urine turns a port wine color after standing
C) Freshly excreted urine is acidic and port wine in color
D) Freshly excreted urine is alkaline and port wine in color

Question

Quizplus · Accepted Answer

The presence of porphobilinogen in the urine can be suspected when acidic urine turns a port wine color after standing for some time. This is known as the Watson-Schwartz test and is a screening test for porphyria. Alkaline urine does not usually give a positive result for this test. Freshly excreted urine may not give an accurate result as porphobilinogen production can occur during storage or standing of the urine.

The Presence of Porphobilinogen in the Urine Can Be Suspected