Detection of Insulin-like Growth Factor-1 (IGF-1) in commercial dairy products

Alessandra Guidi
Department of Animal Pathology Prophylaxis and Food Hygiene
University of Pisa,
Via delle Piaggie 2, 56100 Pisa, Italy

Leopoldo Laricchia-Robbio
Institute of Mutagenesis and Differentiation, CNR
Area della Ricerca S.Cataldo-Ghezzano , 56100 Pisa, Italy.

Laura Anichini
Department of Animal Pathology Prophylaxis and Food Hygiene
University of Pisa,
Via delle Piaggie 2, 56100 Pisa, Italy

Daniela Gianfaldoni
Department of Animal Pathology Prophylaxis and Food Hygiene
University of Pisa,
Via delle Piaggie 2, 56100 Pisa, Italy

The presence of natural IGF-1 in commercial dairy products (cow’s milk and yoghurt) has been evaluated. Immunoenzymatic methods (ELISA and Dot blot) and a surface plasmon resonance-based biosensor system (BIA-technology) were used for detection of Insulin-like Growth Factor-1 (IGF-1) in cows’ milk and yoghurt. Previous studies showed that IGF-1 is augment in milk from cows treated with recombinant bovine Somatropin (rBST). Since IGF-1 is a suspected carcinogen, its presence in dairy products for human consumption is potentially a health hazard. Anti-IGF-1 antibodies were used as tool to probe IGF-1 presence in cows’ milk and yoghurt.

The standardized assay for detecting IGF-1 in fresh cows’ milk previously set up, was used in this study; in total 45 alimentary milk and 27 different yoghurt were analyzed and the IGF-1 levels were monitored.

This study reveals the possibility to separate the analysed products in two sets: the first with IGF-1 levels in the physiological range (up to 5 ng/ml) an the second (more than 5 ng/ml) raising the suspicion to come from treated animals.

This study, based on different traditional immunoassays, has been revealed suitable for application in the dairy industry in the detection of small compounds.