The ELISA (enzyme-linked immunosorbent assay) is a test which uses color change and antibodies to identify a substance. An indirect ELISA is one of three ELISA tests.
Urine varies in appearance, depending principally upon a body's level of hydration, as well as other factors. Normal urine is a transparent solution ranging from colorless to amber but is usually a pale yellow. In the urine of a healthy individual the color comes primarily from the presence of urobilin.
The normal color of the urine varies from pale yellow to straw-yellow. If there is something wrong with your body, urine may be present dark yellow, orange, pink, red, green, blue, brown and even black. Sometimes you may notice the urine is colorless.oo much liquid or caffeine. If your urine is clear or very pale, you may be drinking a lot of liquids or drinking fluids with a high content of diuretics such as caffeine. 2. Diuretics. Medications, containing diuretics, may make your urine colorless, because they force the body to get rid of extra water.