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PubMed1967

African swine fever. II. Detection of the virus in swine tissues by means of the modified direct complement-fixation test.

The modified direct complement-fixation test, supplemented with unheated normal calf serum, was used to demonstrate antibodies in sera of swine immunized to African swine fever virus. These antibodies did not react in the ordinary direct non-supplemented complement-fixation test.African swine fever complement-fixing antigen in infected swine tissue is not denatured by extraction with fat solvents. Consequently, good antigens devoid of non-specific reactivity were obtained by extraction with a mixture of acetone and ether. The virus was detected in infected swine tissue harvested one day after beginning of pyrexia. The modified direct complement-fixation test demonstrated cross-reactions between the six strains of virus studied.

Acetone↗
PubMedDate not supplied

[Serological diagnosis of toxoplasmosis: comparative evaluation of the Sabin-Feldman, indirect immunofluorescence and complement fixation tests].

The AA. compared the indirect immunofluorescence test (IFI), with dye test and complement fixation test (CFT), used in diagnosis of Toxoplasmosis. CFT sensitivity is slightly inferior to that of dye test and IFI; the later give strictly similar results especially at medium and high titers; IFI is more readily and safety performed and easier to interpret.

Antibodies, Bacterial↗
PubMed1975

A mechanism for prozone formation in the complement fixation test for bovine brucellosis.

Complement fixation (CF) by bovine IgG1 or IgM antibodies to Brucella abortus was inhibited by specific non-complement-fixing antibodies of the IgG2 subclass. This inhibition may account for the appearance of prozones in CF titrations of some antiserums, and for the occurrence of serums which are positive to the Rose Bengal test, but negative to the CF test.

Agglutination Tests↗
PubMed1976

A study of the complement fixation test in Salmonella dublin infection.

The complement fixation test was evaluated in a study of Salmonella dublin infection in cattle. In calves vaccinated with a live S dublin vaccine at three days of age, complement fixing (CF) antibodies were not detected in colostrum-fed calves although CF antibodies were detected at low titre in colostrum-deprived calves. In calves vaccinated at three months of age and in experimentally infected cows, CF antibodies persisted for three to six months but serum agglutinin (SA) antibodies persisted at diagnostic titres for longer periods. When serum samples from outbreaks of S dublin infection were examined, the CF results were in agreement with the SAT in the majority of samples obtained from adults and calves suffering from enteric disease. In samples from cases of S dublin abortion, a number of samples had negative CF titres although the SA titres were indicative of infection. Non-specific CF reactions occurred in serum samples from cattle infected with salmonella serotypes other than S dublin.

Agglutination Tests↗
PubMed1976

Comparison of immunodiffusion and complement fixation tests in the diagnosis of histoplasmosis.

The immunodiffusion and complement fixation tests for histoplasmosis were compared on 2,090 initial sera from 70 proven cases of histoplasmosis, 177 routine chest hospital patients, and 1,843 coal miners from outside the major endemic area for histoplasmosis. The complement fixation test using histoplasmin as antigen detected antibodies in the sera of 72.8% of the 70 proven cases, while the complement fixation test using yeast antigen detected antibodies in 94.3% of the case sera, and the immunodiffusion test using histoplasmin antigen detected antibodies in 90% of the sera. The tests were also compared for sensitivity, specificity, and ease of performance.

Antibodies, Fungal↗
PubMed1975

Use of different saprophytic acid-fast bacilli in complement-fixation test for kala-azar.

Complement-fixation tests for kala-azar using antigenic extracts from 4 different saprophytic acid fast bacilli were carried out. It was observed that all the 4 extracts gave positive reactions with sera from kala-azar patients. However, Myco. phlei gave best results and next comes Kedrowsky's bacilli. These two are different strains of the same organism, Myco. phlei. Myco. smegmatis also gave satisfactory results but Myco. butyricum gave weak and false negative reactions in some cases. Last two organisms are the different strains of the same Myco. smegmatis.

Antigens, Bacterial↗
PubMed1977

Demonstration of antibodies to soluble nuclear antigens by complement fixation test. An application of microtiter technique.

The complement fixation test utilizing the microtiter system was applied to study sera from patients with a variety of connective tissue diseases for the presence of antibodies to soluble nuclear antigens. A good correlation was found between microtiter complement fixation and hemagglutination for anti-RNP and anti-Sm antibodies. Anti-Ha antibodies were detected by complement fixation but not by hemagglutination. Different enzyme digestions of the soluble nuclear antigen prior to assay and use of a quantitative microcomplement fixation test were found to improve the analysis of sera with multiple antibodies.

Animals↗
PubMed1976

Studies on the origin of false positive reactions to the complement-fixation test for contagious bovine pleuropneumonia.

Serums of cattle free from contagious bovine pleuropneumonia (CBPP) were tested in complement fixation (CF) tests using 3 antigens; these were the standard antigen (SA) used to test to CBPP in Australia, an ethanol extract antigen (EA) also prepared from Mycoplasma mycoides subsp. mycoides (M. mycoides) and an antigen prepared from a Group 7 bovine mycoplasma isolated from arthritis (AA). The serums included 146 which fixed complement with SA. Eighty percent of these false-positive serums reacted with AA but not with EA; the other 20% were positive at low titre with EA but gave no reaction with AA. Attempts were made to produce false-positive serums experimentally by inoculating 3 Group 7 mycoplasmas and 2 Mycoplasma bovigenitalium strains into cattle. Serums from 3 of 9 cattle inoculated with strain L2917 (Group 7) reacted with SA but differed from the false-positive serums of field cattle by reacting with all 3 antigens. Tests with serums from cattle experimentally infected with CBPP gave similar titres with SA and EA, but the results with AA were mostly negative or less than 10% of the titres obtained with SA and EA. The results of CF tests on serums from the experimental cattle, after absorptions with suspensions of the mycoplasmas, showed that there was a one-way serological relationship between strain L2917 and M. mycoides and between this Group 7 strain and M. bovigenitalium. The CF tests with 3 antigens have assisted in demonstrating the false-positive nature of the reacting field serums encountered in the course of routine CF tests for CBPP in cattle in Australia.

Absorption↗
PubMed1988

New complement fixation test with peroxidase-labeled complement Clq for direct and quantitative determination of antibodies to herpes simplex virus.

An enzyme-labeled complement fixation (ELISA-CF) test for the direct and quantitative determination of complement fixing (CF) antibodies has been developed. This paper described the introduction of the ELISA-CF test that used peroxidase-labeled Clq component of complement to detect CF antibodies which had reacted with herpes simplex virus (HSV), as a virus model. Equal volumes of heat-inactivated serum and the peroxidase-labeled Clq (P*-Clq) were simultaneously added to wells of microplates which had been coated with HSV CF antigen or with cell control antigen. The enzymatic activities of P*-Clq bound to the immune complex were determined photometrically. The ELISA-CF test allows processing of serum specimens in a 3-hr operation, with procedural simplicity and increased specificity and sensitivity compared with the conventional CF test.

Antibodies, Viral↗
PubMed1986

The relationship between the microtitration serum agglutination and complement fixation tests in bovine brucellosis serology.

The relationship between antibody titres in the microtitration serum agglutination test and the complement fixation test in bovine brucellosis is described. For low and high MSAT values there is good agreement between the 2 tests. This is not the case for MSAT values between 54 and 338 IU/ml. For practical reasons, results falling into this category cannot all be repeated. Repetitions are so structured that less than 4% of the tests need to be repeated. If the level of repetitions should show an increase above 4%, it is assumed that technical or human error has occurred.

Agglutination Tests↗