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At least 721 records · Page 40Linked to original sources
PubMed1971

Production and evaluation of a purified adenovirus group-specific (hexon) antigen for use in the diagnostic complement fixation test.

A simple procedure for the production of large volumes of purified adenovirus group-specific complement-fixing (CF) (hexon) antigen by selective adsorption to and elution from CaHPO(4) is described. Results of immunodiffusion tests, electrophoresis, electron microscopy, and tests for hemagglutination and infectivity indicate that the purified antigen consisted of a single virus component (hexon). The purified product contained little host materials. Unlike the crude virus harvest usually employed for serodiagnostic CF tests, the purified antigen demonstrated no anticomplementary activity and did not develop such activity during storage. The purified antigen was equal to or slightly more sensitive than crude virus harvests for serodiagnosis of adenovirus infections.

Adenoviridae↗
PubMed1978

Indirect complement fixation test with foot-and-mouth disease virus antigen concentrated by polyethylene glycol precipitation.

To a BHK-21 cell culture fluid infected with the O, A, or Asia 1 type of foot-and-mouth disease (FMD) virus was added polyethylene glycol 16000 to a concentration of 10% (w/v). Then the fluid was concentrated to one-tenth of the original volume. The resulting concentrated virus antigens showed a complement fixation (CF) titer ranging from 12 to 14. The rate of recovery of CF activity was in a range of 40 approximately 80%. Each antigen was applied to the indirect complement fixation (ICF) test with serum from cattle infected experimentally with the respective type of virus to estimate antibody titers. When antibody was examined for a rise and fall, it began to be detected 4 approximately 7 days after inoculation and was detectable even 63 days after inoculation. It showed a tendency to exhibit a rise and fall parallel with that of neutralizing antibody, although it was always lower in titer than this antibody. ICF antibody corresponding to one type of virus was type-specific, presenting little crossing with a heterologous antigen. As a result, it was clarified that such antigen as prepared from an infected cell culture fluid after concentration with polyethylene glycol was applicable to the ICF test for the estimation of the titer of antibody against FMD virus.

Animals↗
PubMed1986

[Standardization of the complement fixation test (CFT) in brucellosis. IV. Incubation conditions].

A differentiated time and temperature of incubation were used in the first CFT phase. It was found that the activity of complement fixation (C') decreased in the reaction medium. This was observed in the control system in which at 1 C'H50 hemolysis inhibition increase from 50 to 90% was found after 2 hr at 37 degrees C, after 8 hr at 20 degrees C and after 18 hr at 4 degrees C. Simultaneously, a double increase of the standard serum titre was obtained at 4 and 20 degrees C as compared with that at 37 degrees C. At stable concentration of the antigen and complement the effect of C' fixation was the strongest at 4 degrees C, slightly weaker at 20 degrees C and the weakest at 37 degrees C. The above dependence resulted from a different reaction distribution in the chessboard system at each temperature. In the order from the lowest to the highest antigen dilutions positive reactions were increasing and then subsequently expired at 4, 20 and 37 degrees C, forming an optimal antigen dilution typical for each temperature. In our own standard CFT technique a heat and short C' fixation (37 degrees C for 30 min) were chosen which provided the required reaction sensitivity and permitted to make mass diagnostic examinations. It was also shown that the temperature and time of initial incubation of the antigen-antibody complex had no influence on the effect of C' fixation by this complex. This is supported by joint introduction of the antigen and complement into sera.

Animals↗