Description
Serum samples are diluted with a buffer solution. The diluted samples are added into the microtiter plate wells [PLATE] coated with Lactobacillus rhamnosus which metabolizes folic acid.The addition of folic acid in either standards [STD] or samples gives a folic acid dependent growth response until it is consumed.After incubation at 37°C for 48 hours,the growth of Lactobacillus rhamnosus is measured turbidimetrically at 610-630 nm (alternative at 540-550 nm) in an ELISA-reader and a standard curve is generated from the dilution series.The amount of folic acid is directly proportional to the turbidity