We have developed an enzyme-linked immunoabsorbent assay for miraculin, a glycoprotein which is capable of modifying sour taste into sweet. Antiserum against purified miraculin was raised in rabbits and the anti-miraculin in IgG was purified using a Protein A-Cellulofine column and then conjugated with horseradish peroxidase. The established enzyme immunoassay method was able to accurately quantitate pg amounts of miraculin in crude extracts of miracle fruit. The amounts of miraculin in miracle fruit increased dramatically seven weeks after pollination and at eight weeks reached 102 μg/mg protein in the fruit.