Intended use:

Easy to use microbiological microtiter plate test for the quantification of total folic acid (enriched and natural folic acid) in food, feed and pharmaceutical products.

General information:

Folic acid is extracted from the sample and the extract is diluted. The diluted extract and the folic acid assay-medium are pipetted into the wells of a microtiter plate which is coated with Lactobacillus rhamnosus. The growth of Lactobacillus rhamnosus is dependent on the supply of folic acid. Following the addition of folic acid as a standard or as a compound of the sample, the bacteria grow until the vitamin is consumed. The incubation is done in the dark at 37 °C (98.6 °F) for 44 – 48 h. The intensity of metabolism or growth in relation to the extracted folic acid is measured as turbidity and compared to a standard curve. The measurement is done using an microtiter plate spectrophotometer at 610 – 630 nm (alternatively at 540 – 550 nm).