Development of monoclonal antibodies against α-lactalbumin and establishment of qualitative detection for α- lactalbumin with dot blotting assay

The monoclonal antibodies (mAbs) against bovine α-lactalbumin (α-la) were prepared by immunning Balb/c mice and the lymphocyte hybridoma technique. The mAbs were covalently conjugated with the CdSe/ZnS quantum dots (QDs) by the carbodiimide crosslinking method, and then the coupling conditions were optimized. Furthmore, a dot blotting method based on QD-mAb conjugates was established to qualitatively detect α-La in different commercial dairy products. The results showed that the prepared mAbs had high specificity and no cross-reaction. A good coupling effect was confirmed when the molar ratio of QD, N- (3-Dimethylaminopropyl) -N'-ethylcarbodiimide hydrochloride (EDC) , N-Hydroxysuccinimide (NHS) , monoclonal antibody was 1∶10∶6∶4. The developed method based on QD-mAb conjugates could be used to visual, rapid qualitative analyze α-La in dairy products. Accordingly, the method possesses certain practical value.