Preparation of antibodies type IgY against Salmonella typhi lipopolysaccharide in chicken eggs

Lipopolysaccharide was extracted from local isolate Sallmonella typhi (previously isolated and characterized) by hot EDTA method, and the extract was partially purified by gel filtration chromatography on sepharose Cl-6B gel. The results showed that the percentage of the carbohydrates amount in the partially purified LPS extract was 43.7%, while the percentage of binding proteins in the same extract was 0.7% with no nucleic acids was found. The molecular weight for the LPS was measured by the gel filtration chromatography method using Sepharose Cl-6B gel and was equivalent to 263000 Dalton. The LD50 of LPS was determined by injection of chicken embryos type Ice Brown in the charioallantoic membrane, and was 14.66 μg/Kg. In order to obtain anti S. typhi IgY antibodies, chickens were immunized with the partially purified S. typhi subcutaneously. The IgY antibodies were extracted from eggs yolk by water dilution method and the extract was partially purified by ammonium sulphate precipitation at ratio 60% saturation, and gel filtration chromatography on sepharose Cl-6B gel. The results showed that the protein amount was equivalent to 23.5 mg/ml; specific activity was 0.268, and an overall yield of 70%. The molecular weight for the IgY antibodies was measured by the gel filtration chromatography method using Sepharose Cl-6B gel and was found to be 178000 dalton. The concentration of anti S.typhi LPS IgY antibodies in chicken eggs were investigated by ELISA and was found to be 6.3 mg/ml, and there is a significant differences (P 0.01).