Was the test positive or what?
Evaporation (“evap”) lines result with the test’s antibody strip just looks slightly different than the space around it. There is a line of antibodies (usually made from mouse cells) in the Control and Test section. The Control line binds with any liquid and turns pink (or blue, in tests using blue dye.) The Test/Result line turns pink only if pregnancy hormone is detected. If not, the moisture passes over this strip and does not turn pink. It may, however, become more visible when the light hits the moisture on the strip– it may appear gray, colorless, like a “dent” in the test, or like a “ghost line.” It may appear at any time– as soon as the urine hits it, after a few minutes as the test absorbs the moisture, or after the 10-minute time limit. It may appear when the test is drying, or after it has dried. It may disappear as the test is drying, or after the test has dried, or not disappear at all. The simple fact is that there is always “something there” that is slightly visible–