Creatinine, Random Urine

Additional Information:

UFHPL Epic order code: LAB384

CPT Code(s):


Specimen Requirements:

Type: Urine, random

Container/Tube: Plastic urine container with no preservative

Sample Volume: 1 mL

Storage: Refrigerate specimens.

Specimen Retention Time: 5 days


This creatinine procedure is a kinetic modification of the Jaffe procedure, in which creatinine reacts with picric acid at alkaline pH to form a yellow-orange complex. However, this reaction is not completely specific for creatinine, since other reducing substances, such as glucose, pyruvate, ascorbic acid, and acetoacetates, will react with picrate to form a similar color. Fabiny and Ertingshausen found that alkaline creatinine picrate reaches maximum color development at a different rate than pseudo-creatinine material. Cook utilized different reaction rates of alkaline picrate positive substances to obtain greater specificity with the Jaffe reaction. The rate of change in absorbance at 520/800nm is proportional to the creatinine concentration in the sample.


Within 3 days

Reference Values:

No reference range established