Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 46

Shortly after arriving for the day shift in the urinalysis laboratory, a technician notices that an undiscarded urine has a black color. The previously completed report indicates the color to be yellow.

a. Is this observation significant? Explain your answer.

b. The original urinalysis report showed the specimen to be positive for ketones. Is this significant? Why or why not?

c. If the ketones are negative and the pH is 8.0 is this significant? Why or why not?

Step 1 of 3

a.

, the observation is significant.

• Presence of homogentisic acid or melanin produces black color in urine on standing

• Melanin is a pigment produced from melanogen and homogentisic acid is the metabolite of phenylalanine