The sensitive measurement of total rat prorenin and renin antigen is easily performed with this 96 well strip format ELISA kit. Rat prorenin and renin in plasma, serum, urine or cell culture media binds capture antibody coated onto a micro titer plate. Anti-rat prorenin primary antibody binds to the captured prorenin. Excess antibody is washed away, and bound antibody is then reacted with the secondary antibody. TMB substrate is used for color development at 450 nm. All reagents and standards are provided in these ELISA kits.