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 color of urine can vary from almost colorless to black. Normal urine may show color variation ranging from pale yellow to deep amber. Urine color is typically a result of the degradation of the heme molecule into a urinary pigment called urochrome.he color of urine can vary from almost colorless to black. Normal urine may show color variation ranging from pale yellow to deep amber. Urine color is typically a result of the degradation of the heme molecule into a urinary pigment called urochrome.