The mannitol fermentation test is used to test if a microbe can ferment the carbohydrate mannitol as a carbon source. If mannitol has been used by the microbe, acidic byproducts will be produced and the pH of the medium ... More »

Sugars do not produce positive results in a fermentation test. Fermentation is the process in which sugars are converted into a different chemical product. In a fermentation test, specific sugars are used to determine th... More »

Biochemical tests for identifying bacteria generally break down into two categories: gram positive tests and gram negative tests. Many tests exist in these two general categories; gram positive tests include catalase, Ma... More » Science Biology Cells

A citrate test determines if a microbe can grow by using citrate as its only source of energy and carbon. If the microbe grows on Simmons citrate agar, it passes the test. More »

BabyCenter reports that a faint line on an EPT test is considered to be a positive result as long as the test is read within the specified time frame. Faint positives are generally due to low levels of human chorionic go... More »

A pregnancy test cannot be taken online, since a blood or urine sample is required. Tests detect the presence of the human chorionic gonadotropin hormone in a woman's body, which indicates pregnancy, according to WebMD. More » Health Women's Health Pregnancy

Home pregnancy test kits are designed for a single use and cannot be reused. The home pregnancy test has a special platform that is treated with an antibody that will bind with the hormone HCG in a pregnant woman's urine... More » Health Women's Health Pregnancy