Why is the peptide solution coupled to carrier protein occasionally turbid?

Commonly used carrier proteins include hemocyanin (KLH), bovine serum albumin (BSA) and ovalbumin (OVA). Due to the large molecule and complex structure of the carrier protein, its water solubility is limited, resulting in a small number of polypeptide conjugates. After the carrier protein is linked, a flocculent suspension will appear in the solution, which is not completely clear and transparent. In general, this does not affect its immunogenicity, and the cloudy solution can be used for the immune response.