Blood sera, immunodiffusion

A copper-binding protein, ceruloplasmin, which is a blood serum protein, has been demonstrated in milk by immunodiffusion techniques (Hanson et al. 1967 Poulik and Weiss 1975). It may be the enzyme ferroxidase (EC 1.16.3.1). 

By Spies ( ) classification, PN-IA is heat-stable whereas PN-IB is heat-sensitive and would be destroyed in the roasting process. PN-IA is present in extremely low amounts in the seed. We examined raw and roasted peanut allergen extracts using blood serum of two sensitive individuals as the source of antibody. The immunodiffusion reaction between the peanut allergen and antibodies in their blood produced a sharp precipitin arc, but the precipitin arc disappeared after saline deproteination of the gel on the glass plate. No precipitin arc occurred with blood from... 

Figure 7. Immunodiffusion of normai and byssinotic blood sera against human IgG antibodies. Tripatigen plate contains antibodies to human IgG in gel. Key well 1, control IgG serum provided with plates well 2, normal human serum well 3, serum from byssinosis patient.

One can be relatively certain that a protein will be immunogenic if it has a molecular weight >10,000 and if it is immunochemi-cally foreign to the animal receiving the antigen. One should also consider the ultimate use of the antibody when choosing the carrier protein. For instance, human serum albumin would be a poor carrier for a hapten if the resulting antibody were to be used to monitor human blood samples by immunodiffusion. 

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