CM LAB - Laboratory Correlations of Urine Color II

Question 1

Red

Clear urine with positive chemical test results for blood; muscle damage

Answer 1

myoglobin

Question 2

Red

Alkaline urine of genetically susceptible persons

Answer 2

Beets

Question 3

Red

Tuberculosis medication

Answer 3

Rifampin

Question 4

Red

Cloudy specimen with RBCs, mucus, and clots

Answer 4

Menstrual contamination

Question 5

Port wine

Negative test for blood, may require additional testing

Answer 5

Porphyrins

Question 6

Red-brown

Seen in acidic urine after standing; positive chemical test result for blood

Answer 6

RBCs oxidized to methemoglobin

Question 7

2 possible colors of urine with myoglobin

Answer 7

Red

Red-brown

Question 8

Brown

Seen in alkaline urine after standing; specific tests are available

Answer 8

Homogentisic acid (alkaptonuria)

Question 9

Black

Urine darkens on standing and reacts with nitroprusside and ferric chloride

Answer 9

Malignant melanoma

Melanin or melanogen

Question 10

Black

Interfere with copper reduction tests

Answer 10

Phenol derivatives

Question 11

Black

Color disappears with ferric chloride

Answer 11

Argyrol (antiseptic)

Question 12

Black

Antihypertensive

Answer 12

Methyldopa or levodopa

Question 13

Black

Darkens on standing, intestinal and vaginal infections

Answer 13

Metronidazole (Flagyl)