For an IgE-mediated allergic reaction to occur in response to a food protein, the protein must be large enough to create a bridge between two IgE-antibody molecules.  Protein size is measured using molecular weight and reported using Daltons or kilo Daltons.  Proteins in cow's milk formula range between 10,000 and 70, 000 Daltons (1).  The process of protein hydrolysis and filtration reduces protein size.  Generally, the more extensive the hydrolysis and ultrafiltration, the