The invention belongs to the field of a nano-
biotechnology and particularly relates to a method for marking immune
globulin by a
quantum dot. The method comprises the following steps: washing the
quantum dot, activating, washing the
quantum dot for the second time, washing the immune
globulin,
coupling and separating. According to the method, structural characteristics of the water-soluble
quantum dot, the reaction characteristics of EDC (1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide
hydrochloride) activated carboxyl and the reaction characteristics of a
condensation reaction are utilized; the carboxyl on the surface of the
quantum dot is activated sufficiently by optimizing conditions of all the steps and is in a suitable marking environment; the
quantum dot can be combined with the surface of the immune
globulin by the
condensation reaction through optimizing the condition of the
coupling step, and the marking efficiency is high. The immune globulin which is not reacted can be recycled to be marked continually through exclusion
chromatography, separation and purification by a reaction solution obtained by the
coupling step so that the
utilization rate of the immune globulin is improved and the cost is saved. According to the method provided by the invention, the activity of a prepared
protein-quantum dot conjugate is high, the operation and used equipment are simple, and the production can be enlarged industrially.