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.
Tweet. Urine typically has a straw-yellow color although this may vary at times to a pale yellow or slightly darker yellow. At times, urine may be almost clear in color especially in a person who is urinating frequently like when using a diuretic (water tablet), consuming alcohol and drinking excessive amounts of water.