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Lab Dept:
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Urine/Stool
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Test Name:
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REDUCING SUBSTANCES, URINE
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General Information
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Lab Order Codes:
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URS
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Synonyms:
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Urine Reducing Substance; Carbohydrate, urine; Disaccharide screening; Monosaccharide screening
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CPT Codes:
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81002 – urinalysis, by dip stick or tablet, non-automated, without microscopy
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Test Includes:
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Reducing substance in urine
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Logistics
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Test Indications:
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Useful for detecting any reducing substance in urine which may be present as a result of an inherited metabolic disorder.
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Lab Testing Sections:
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Urinalysis
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-6280
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651-220-6550
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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2 hours
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Special Instructions:
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Send to lab within 30 minutes of collection.
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Specimen
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Specimen Type:
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Urine
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Container:
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Urine cup
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Draw Volume:
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12 mL (Minimum: 1 mL) urine
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Processed Volume:
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Entire volume submitted
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Collection:
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A specimen collected by catheterization is optimal; however, a clean-catch or mid-stream specimen is also acceptable. Random, voided specimens will be accepted, but are the least desirable and are not recommended if a urine culture is also being requested. In all cases, a first morning specimen is most desirable.
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Special Processing:
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Transport immediately since glucose and other reducing substances are consumed by bacteria. Refrigerate specimen if it cannot be transported or processed immediately.
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Patient Preparation:
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Collect a clean-catch urine specimen as follows:
Males: Clean glans with soap and water. Rinse area with wet gauze pads. While holding foreskin retracted, begin voiding. After several mL’s have passed, collect midstream portion without stopping flow of urine. Place the cap on the cup and tighten securely. Refrigerate specimen after collection and promptly forward to the lab.
Females: Thoroughly clean urethral area with soap and water. Rinse area with wet gauze pads. While holding labia apart, begin voiding. After several mL’s have passed, collect midstream portion without stopping the flow of urine. Place the cap on the cup and tighten securely. Refrigerate specimen after collection and promptly forward to the lab.
Note: Indicate type of specimen (catheterized or void) and time of collection on the label.
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Sample Rejection:
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<1 mL urine submitted, contamination with feces; urine in cotton balls; specimen decomposition (e.g., pH >9.0); bacterial overgrowth; mislabeled or unlabeled specimens
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Interpretive
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Reference Range:
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Negative
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Critical Values:
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N/A
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Limitations:
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Clinitest is not specific for glucose and will react with sufficient quantities of any reducing substance in the urine. These include lactose, fructose, galactose, and pentoses.
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Methodology:
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ClinitestŪ, Copper Reduction Tablet Test
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Contraindications:
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Interfering Substances:
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Creatinine/Urine Acid
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May cause false positive
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Homogentisic Acid
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Positive
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Ascorbic Acid (large amounts)
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False trace positive (false positive, brown color)
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Cephalosporins (Keflin, etc)
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Negative
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L-Dopa (large amounts)
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False positive
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Nalidixic Acid
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False positive
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Probenecid
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False positive
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x-ray dye (diatrizoates)
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Black color
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Hydrogen peroxide
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May inhibit positive test
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Note: Other drugs implicated in copper reduction are amino acids, caronamide, choral, chloroform, chloramphenicol, formaldehyde, hippuric acid, isoniazid, thiazides, oxytetracycline, p-aminosalicylic acid, penicillin, phenols, streptomycin, phenothiazine and sulfonamides.
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References:
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Bruist NR, British Medical Journal 2:745
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ClinitestŪ Package Insert, Bayer Corporation, Diagnostic Division
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Strasinger SK (1989) Urinalysis and Body Fluids, 2nd ed, FA Davis Company
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