Cystine Analysis - Urine Amino Acid Qt.

Also known as: cystine urine test, urine amino acids, UAA, amino acid 24 hour urine.

What is cystine analysis?

Amino acids (of which cystine is one) are the building blocks for all the proteins that the body uses to make tissues and hormones. When proteins are broken down, the amino acids formed are normally reabsorbed in the kidneys and reused to perform a wide variety of bodily functions. Testing for amino acids, which are abnormally excreted in the urine helps identify body function imbalances that can occur from inherited or acquired diseases.

Cystine is a compound that forms in crystals in the kidneys, ureters and bladder from a specific inherited disease of an amino acid passed down from parent to child through a defect in their genes.

Cystine analysis – urine amino acid qt. is a test of the urine that examines amino acid levels, including cystine. A high level of cystine in the urine is a risk factor for stone formation in the urinary tract.

What happens during the procedure?

Cystine analysis – urine amino acid qt. is typically a 24-hour urine test. That means all urine is collected from the child over a 24-hour period.

Is any special preparation needed? 

It is typically recommended that a person drink 6 to 8 glasses of water before the test to aid in urination.

What are the risk factors?

There are no risk factors related to the test.

Reviewed by: Jack Wolfsdorf, MD, FAAP

This page was last updated on: July 27, 2022 12:54 PM


The Division of Nephrology at Nicklaus Children’s Hospital treats kidney disorders and provides comprehensive evaluation of renal functions, including kidney biopsies.

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