There are five primary color-tests reagents used for general screening purposes. The Marquis reagent turns into a variety of colors when in the presence of different substances. Dille-Koppanyi reagent uses two chemical solutions which turns a violet-blue color in the presence of barbiturates. Duquenois-Levine reagent is a series of chemical solutions that turn to the color of purple when the vegetation of marijuana is added. Van Urk reagent turns blue-purple when in the presence of LSD. Scott Test's chemical solution shows up as a faint blue for cocaine base. 
Women who are trying to get pregnant or think they are pregnant will find home pregnancy urine analysis kits not only convenient, but also affordable and efficient. Pregnancy urine test looks for the presence of hCG (Human Chorionic Gonadotropin) - a hormone that is produced during pregnancy - in the urine sample. Many obstetricians also perform urine test on pregnant women to know for sure the cause of symptoms. These pregnancy test kits usually delivers results in as 2 minutes and the earlier that a pregnancy is detected, the better the expectant mom can seek for appropriate prenatal care. Here at TestCountry, your options for pregnancy test range from the conventional test strips to pregnancy cassette test.