Determination of PGE2 and cytokine marker levels in rat paw edema exudates

Prostaglandin E₂ (PGE₂) level in carrageenan-challenged paw edema exudates were determined using the PGE₂ ELISA kit assay. The experimental animals from the entire group were sacrificed using excess thiopental sodium after 3 h; carrageenan challenge and hind paws were excised and inflammatory exudates were collected from centrifugation of excised hind paw [19]. In brief, a substrate solution was added to the assay wells and incubates for color development and the reaction is stopped to measure color intensity at 450 nm. All the reagents and sample preparation was done as per the kit assay procedure [20].

Eight different inflammatory cytokine marker levels of rat paw edema exudates were determined using signosis Rat Inflammation ELISA strip assay (catalog no: EA-4002). In brief, control or test samples were added and incubated to each well coated with primary antibody against cytokine then washed with assay buffer. Add biotin-labeled antibody to each well followed by streptavidin-HRP conjugate and substrate solution to incubate with gentle shaking for color development. The reaction was terminated by adding the stop solution. The density of the color developed was read at 450 nm using a microplate reader within 30 min of the assay. PGE₂ level were expressed as pg/ml of rat paw exudates whereas all other cytokine levels were expressed in relation to optical density at 450 nm of rat paw exudates.