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.
According to medical experts, pale yellow to dark amber is the color of normal urine. However, it is an ideal scenario wherein, most people may have normal urine. There are various factors which can change the color of the urine. They include certain food sources, medications or some diseases.bnormal urine color could be brown, orange, dark yellow, pink or red, blue or dark green, purple, and cloudy or murky. As mentioned at the beginning of the article, pale yellow to deep amber is an identifying characteristic of normal urine.