Ace eia kit

This assay (ACE EIA kit, Cayman Chemical, Ann Arbor, MI, USA) was based on the competition between the LTE₄ and the LTE₄–acetylcholinesterase (AChE) conjugate (LTE₄ tracer) for a limited amount of LTE₄ antiserum. Because the concentration of the LTE₄ tracer was held constant while the concentration of the LTE₄ varied, the amount of LTE₄ tracer that was able to bind the LTE₄ antiserum was inversely proportional to the concentration of the LTE₄ in the well. This antibody-LTE₄ complex was bonded to a mouse monoclonal antirabbit IgG that had been previously attached to the well. The plate was washed to remove any unbound reagents and then Ellman’s reagent (which contains the substrate to AChE) (Cayman Chemical) was added to the well. The product of this enzymatic reaction had a distinct yellow color and absorbed strongly at 420 nm. The intensity of this color determined spectrophotometrically was proportional to the amount of LTE₄ tracer bound to the well, which was inversely proportional to the amount of free LTE₄ present in the well during the incubation, according to the equation by Haus et al:5 (link)