An enzyme immunoassay for the quantitative measurement of connective tissue growth factor (CTGF) in serum. The DRG CTGF ELISA Kit is a solid phase enzyme-linked immunosorbent assay (ELISA) based on the sandwich principle. The microtiter wells are coated with a polyclonal [goat] antibody directed towards a unique antigenic site of the CTGF molecule. Together with assay buffer an aliquot of patient sample containing endogenous CTGF is incubated in the coated well. After incubation the unbound material is washed off. A second incubation with antiserum and a washing step follows. Enzyme conjugate, which is a goat anti rabbit antibody conjugated with horseradish peroxidase is added. After incubation the unbound conjugate is washed off. The amount of bound peroxidase is proportional to the concentration of CTGF in the sample. Having added the substrate solution, the intensity of colour developed is proportional to the concentration of CTGF in the patient sample.