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Biomedical subjects

R B Fritz

Publications and source records attributed to R B Fritz.

68 records · Page 4Linked to original sources
PubMed1974

Enzymatic radioiodination of the envelope proteins of avian myeloblastosis virus.

Purified avian myeloblastosis virus was iodinated by the lactoperoxidase method. Disruption of the labeled virions and chromatography of the viral proteins showed that radioiodine was associated only with the glycoproteins of the viral envelope. Reaction of the radiolabeled virus with antiviral antibody followed by mild detergent treatment and subsequent recovery of immune complexes showed this technique to be useful for the isolation of viral envelope antigens.

Animals↗
PubMed1973

Avian oncornavirus group-specific antigen: detection and quantification by radioimmunoassay.

A double-antibody competitive-inhibition radioimmunoassay for avian group-specific antigen is described. A viral protein preparation, consisting primarily of gs-1, was labeled with radioiodine. Hamster and rabbit antisera were reacted with the labeled antigen, and the resultant antibody-antigen complexes were precipitated with the appropriate antiglobulin. Standard curves based on the inhibition of binding of labeled antigen to antibody after preincubation with unlabeled antigen were prepared. These showed the lower limit of sensitivity to be 2 to 10 ng of unlabeled protein when labeled antigen of 2,000 to 5,000 counts per min per ng of specific activity was used in the assay. Extracts of avian oncornavirus-infected cells, likewise, were able to inhibit binding of labeled antigen. This technique will be very useful for the quantification of small amounts of oncornavirus group-specific protein.

Alpharetrovirus↗
PubMed1969

Reaction of chick embryo cells infected with leukosis strain MC29 virus with fluorescein-labeled antibody.

Immune serum was prepared in the rabbit with BAI strain A leukosis virus isolated by centrifugal fractionation from the plasma of chickens with myeloblastic leukemia and further purified on a potassium tartrate gradient. Antibody to group-specific antigen was demonstrated in the serum by immunoelectrophoresis and immunodiffusion. Fluorescein-conjugated serum was used unabsorbed and absorbed with chick cells for study of acetone-fixed chick embryo cells uninfected or infected with strain MC29 avian leukosis virus. With unabsorbed serum, large numbers of cytoplasmic particles stained in a few cells within 2 hr after exposure to virus, and the cell number increased greatly in 24 hr. Absorption of the serum abolished the early reaction. Staining with absorbed serum was delayed until about 14 hr after culture exposure to virus, but essentially all cells were stained within 72 hr at the time when all cells were morphologically altered. Differences between the responses to unabsorbed and absorbed serum suggested cytoplasmic formation or concentration of chick tissue antigen similar to that incorporated in leukosis virus particles. The characteristics of staining with absorbed serum were similar to those observed by others in analogous studies with avian tumor viruses.

Animals↗