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.
TANITH CAREY talked to the experts to find out what the colour of your urine really means. Urine is usually pale yellow - the colour comes from urochrome, a yellow pigment that's a by-product when bile, a greenish-coloured liquid, is broken down. Bile is produced by the liver and helps us digest fats.