General Tetrahydrofolic Acid ELISA Kit

From Antibodies.com, this competitive Enzyme-Linked Immunosorbent Assay (cELISA) is intended for the in vitro quantitative determination of Tetrahydrofolic Acid in serum, plasma, tissue homogenates, cell lysates, cell culture supernates and other biological fluids [S1].

The 96-well microtiter plate is pre-coated with Tetrahydrofolic Acid antigen. Tetrahydrofolic Acid present in samples or standards competes with the immobilised antigen for binding sites on a Biotinylated Anti-Tetrahydrofolic Acid Antibody. After washing, an HRP-Avidin conjugate is added; TMB substrate is then used to visualise the HRP reaction, producing a blue product which turns yellow upon addition of acidic stop solution. Yellow intensity is inversely proportional to the Tetrahydrofolic Acid concentration, quantified by O.D. absorbance at 450 nm in a colorimetric microplate reader [S1].

The kit has a reported product range of 3.12–200 ng/ml and a sensitivity of 0.92 ng/ml, with a total assay time of 2 h 30 m [S1]. Reported recovery in serum (n=5) was 80%–102% (average 91%), in EDTA plasma (n=5) 81%–100% (average 90%) and in heparin plasma (n=5) 80%–89% (average 84%) [S1]. Kit components should be stored at +4 °C or –20 °C as instructed and not used past the kit's expiration date [S1].