Sarcosine-to-Creatinine Ratio, 24-Hour Urine
Measures sarcosine relative to creatinine in urine collected for 24 hours to help evaluate elevated sarcosine excretion and possible sarcosinemia.
["An elevated urine sarcosine-to-creatinine ratio may indicate a disorder of sarcosine metabolism, but results must be interpreted with symptoms and other tests."]
Key facts at a glance
- LOINC
- 25978-8
- Short code
- Sarcosine/Creat 24h Ur-sRto
- Synonyms
- Sarcosine/Creat 24h Ur-sRto
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures the amount of sarcosine in urine compared with the amount of creatinine. Sarcosine is a nonessential amino acid made during metabolism of creatine, and the ratio helps account for differences in urine concentration.
Why might I need this test?
The test may be used to investigate unusually high sarcosine levels or possible sarcosinemia, an inherited metabolic condition. It may be ordered for children with developmental delays, seizures, unusual behavior, or other symptoms suggesting a metabolic disorder.
How is the test performed?
You collect all urine for exactly 24 hours, usually in a labeled container provided by the laboratory. The laboratory measures sarcosine and creatinine and calculates their ratio.
How do I prepare for the test?
Follow the collection instructions carefully, including the start and finish times and whether the container should be refrigerated. Maintain your usual diet and fluid intake unless your clinician or laboratory gives different instructions, and note any missed collections.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated ratio may indicate increased sarcosine production or reduced breakdown of sarcosine, as can occur in sarcosinemia. A low or normal ratio does not by itself establish or exclude a metabolic disorder, and results should be interpreted with urine amount, kidney function, symptoms, diet, and other laboratory findings.
Short name
24-Hour Urine Sarcosine/Creatinine Ratio
Frequently asked questions
What does the sarcosine-to-creatinine ratio show?
Does sarcosinemia usually cause symptoms in infancy?
Can this test be performed on a random urine sample?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy