IgY Technology: Extraction of Chicken Antibodies from Egg Yolk by Polyethylene Glycol (PEG) Precipitation

Hens can be immunized by means of i.m. vaccination (Musculus pectoralis, left and right, injection volume 0.5-1.0 ml) or by means of Gene-Gun plasmid-immunization. Dependent on the immunogenicity of the antigen, high antibody-titres (up to 1:100,000 - 1:1,000,000) can be achieved after only one or 3 - 4 boost immunizations. Normally, a hen lays eggs continuously for about 72 weeks, thereafter the laying capacity decreases. This protocol describes the extraction of total IgY from egg yolk by means of a precipitation procedure (PEG. Polson et al. 1980). The method involves two important steps. The first one is the removal of lipids and the second is the precipitation of total IgY from the supernatant of step one. After dialysis against a buffer (normally PBS) the IgY-extract can be stored at -20°C for more than a year. The purity of the extract is around 80 %, the total IgY per egg varies from 40-80 mg, dependent on the age of the laying hen. The total IgY content increases with the age of the hen from around 40 mg/egg up to 80 mg/egg (concerning PEG precipitation). The laying capacity of a hen per year is around 325 eggs. That means a total potential harvest of 20 g total IgY/year based on a mean IgY content of 60 mg total IgY/egg (see Table 1).     

Phylogenetic study of serotonin-immunoreactive structures in the pancreas of various vertebrates

Summary The distribution pattern of serotonin (5HT) in the pancreas was studied immunohistochemically by using a 5HT monoclonal antibody in various vertebrates including the eel, bullfrog, South African clawed toad, turtle, chicken, mouse, rat, guinea-pig, cat, dog and human. In all species examined, except the bullfrog, 5HT-like immunoreactivity was observed in nerve fibers, in endocrine cells, or in both. Positive nerve fibers were found in the eel, turtle, mouse, rat and guinea-pig. These fibers ran mainly along the blood vessels and partly through the gap between the exocrine glands. In the eel and guinea-pig, positive fibers invaded the pancreatic islet. Occasionally, these positive fibers were found adjacent to the surface of both exocrine and endocrine cells, suggesting a regulatory role of 5HT in pancreatic function. 5HT-positive endocrine cells were observed in the pancreas of all species except for the bullfrog and rat. In the eel and in mammals such as the mouse, guinea-pig, cat, dog and human, 5HT-positive cells were mainly observed within the pancreatic islet. In the South African clawed toad, turtle and chicken, the positive cells were mainly in the exocrine region. The present study indicates that the distribution patterns of 5HT in the pancreas varies considerably among different species.