5-hydroxyindoleacetic acid

5-hydroxyindoleacetic acid (5-HIAA) is a metabolite of human 5-HT. Generally, the 5-HIAA content in urine is determined by chemical colorimetry to diagnose carcinoid tumors. The basic principle is: 5-HIAA is coupled with 1-nitroso-2-naphthol and nitrous acid in purple, and the color depth is proportional to the 5-HIAA content in urine, because normal human urine is generally not obvious. Purple, so qualitative tests can meet the needs of clinical diagnosis.