Uric acid

Uric acid (Acidum uricum, C5H403N4) - weak acid, almost insoluble in cold water, but when alkalization of water is easily dissolved, forming uric acid salts - urates.
Uric acid is a permanent part of urine and blood. In some pathological conditions (for example, at a gout, arthritis, bursitis, and so on) urate crystals are deposited in the cartilage, tendons, and in the form of sand and stones in the bladder and kidneys.
Night person produces urine 0.5-1 g of uric acid. In blood serum of healthy people there are from 2 to 4 mg% of uric acid.
Discover uric acid can evaporation mixture of urine diluted nitric acid and wetting balance ammonia solution: you receive purple staining (the so-called muriksina test).