Tamm-Horsfall Protein (Uromodulin)
Definition
The most abundant protein in normal human urine, secreted exclusively by cells of the thick ascending limb of Henle's loop in the kidney. Used as an immunological marker to confirm the presence of urine in forensic stains.
- Field
- Forensic serology, body fluid identification
- Also known as
- Uromodulin
- Source
- Thick ascending limb of Henle's loop in the kidney
- Forensic use
- Immunological marker confirming presence of urine in stains
Common questions
Why is Tamm-Horsfall protein a reliable marker for urine specifically?+
It is secreted almost exclusively by kidney tubule cells and reaches high concentration in urine, unlike enzymes or proteins that appear across several body fluids. Its near-exclusivity to the urinary tract makes a positive result more specific than markers shared between fluids.
Does a negative Tamm-Horsfall test rule out urine in a stain?+
Not with certainty. Protein degradation from age, heat, microbial activity, or small sample size can reduce detectable levels below the assay threshold even when urine was originally present, so examiners weigh a negative result alongside other physical and chemical evidence.
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Explained in these topics
- Immunological Identification of Vaginal Secretions, Urine, and Other Fluids
- Urine and Sweat IdentificationThe most abundant urinary protein in healthy individuals, produced exclusively by epithelial cells of the loop of Henle and excreted into urine. Its kidney-spe...