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At least 19 recordsLinked to original sources
PubMed1987

Quantitative estimation of diphtheria and tetanus toxoids. 2. Single radial immuno-diffusion tests (Mancini) and rocket immuno-electrophoresis test in comparison with the flocculation test.

The concentration in Lf units, of an unknown diphtheria or tetanus toxoid preparation is estimated in the flocculation test relative to reference preparations of tetanus and diphtheria antitoxins, respectively. By replacing the antitoxin reference preparations with toxoid reference preparations it should be possible to use immunological methods other than the flocculation test for the quantitative estimation of toxoids in Lf units. A number of diphtheria and tetanus toxoids were tested by rocket immuno-electrophoresis and single radial immuno-diffusion (Mancini test). The concentrations of the unknown toxoids were expressed relative to a diphtheria toxoid calibrated in Lf units (DIFT) and a tetanus toxoid calibrated in Lf units (TEFT), respectively. These two toxoid preparations are regarded as candidates for establishment as international standard preparations. The results obtained in the two tests were compared with those obtained in the flocculation test. In most cases the differences between the results did not exceed 10%. It is concluded, therefore, that the rocket electrophoresis or the radial immuno-diffusion tests can be used as alternatives to the flocculation test.

Diphtheria Toxoid↗
PubMed1975

A rapid slide flocculation test for the diagnosis of American trypanosomiasis using Trypanosoma cruzi fragments preserved by lyophilization. Comparison with hemagglutination, immunofluorescence, and complement fixation tests.

A slide flocculation test for Chagas' disease is described, which uses a lyophilized, stable antigen obtained by formalin and ultrasonic treatment of culture forms of Trypanosoma cruzi. The test was compared with other tests for the serodiagnosis of American trypanosomiasis and showed a high sensitivity, positive results being obtained in every case of acute or chronic Chagas' disease. In sera from blood donors and from normal individuals with negative T. cruzi antigen complement fixation tests a specificity of 96% was found. False positive flocculation tests were seen, especially in cases of South American blastomycosis and in a few cases of acute toxoplasmosis. Since it is easy and quick to perform, the slide flocculation test can be recommended as a screening procedure, especially for blood banks.

Bacterial Infections↗
PubMed1978

[Use of an immunofluorescence method and a flocculation test with DNA-sensitized bentonite particles in the serodiagnosis of disseminated lupus erythematosus (SLE)].

The determination of antibodies against native DNA is of great importance in the solution of the diagnostic and therapeutic problems of dissiminated lupus erythematodes. The practical results are in a direct dependence on the laboratory methods for their determination. The diagnostic significance of two methods was studied with the present investigation: indirect immunofluorescent test and flocculation test with DNA-sensibilized bentonite particles. Under the conditions of the investigation, with the aid of the first method, antibodies against native DNA were found in 86.1 per cent of the sera of lupus nephropathy patients as well as in 13.3 per cent of the sera of patients with renal diseases not associated with LED. High serum titres including up to 1/128, were observed only in LED cases. The continuous persistence of antibodies against LED is also characteristic for the latter. The flocculation test was positive in 60.7 per cent of the sera investigated only with LED cases. The conclusion is that both methods could more wisely be used in LED immunodiagnostic because they combine high sensitivity with specificity of reaction, are easy to perform and no expensive material and apparatuses are required.

Adolescent↗
PubMed1973

An appraisal of the bentonite flocculation test in the detection of bovine tuberculosis.

In this further study, an exhaustive investigation into the value of the bentonite flocculation test in detecting tuberculosis in cattle was made on a group of 358 cattle, with known intradermal (ID) tuberculin reactions and with or without tuberculosis lesions. Bentonite sensitized with human old tuberculin (OT) and a purified BCG carbohydrate fraction (BCG-F1) were used. In the group of 126 cows with tuberculosis lesions, 113 were positive to the tuberculin ID test and there were also 113 positive reactions to the flocculation test using OT sensitized bentonite. Only 62 were positive using the BCG-F1 sensitized bentonite. Out of the 232 animals with no visible lesions, 114 reacted positively to the tuberculin ID test, 148 had a titer to the flocculation test using OT sensitized bentonite and 70 were positive when using BCG-F1 sensitized bentonite.

Animals↗
PubMed1976

Preliminary observations on the use of the capillary flocculation test for the diagnosis of heartwater (Cowdria ruminantium infection).

A capillary flocculation test was developed to diagnose heartwater disease of ruminants. Antigen was prepared from the brains of cattle and goats highly infected with Cowdria ruminantium. Sera were obtained from experimentally infected ruminants which either recovered naturally or with the aid of oxytetracycline treatment. Antibodies were first detected one to two weeks after clinical recovery or after treatment, and persisted for periods varying between one and four weeks. Control sera collected from cattle (sheep) and goats in the Netherlands where heartwater does not occur, or from animals serologically positive for Anaplasma marginale or Eperythrozoon ovis infections, did not react to the test.

Animals↗
PubMed1965

Value of the Jirgl flocculation test in the diagnosis of jaundice.

The Jirgl flocculation test has been compared with the combination of the thymol reactions and serum alkaline phosphatase determination recommended by Maclagan in the investigation of 68 patients with jaundice. The test was found to be of value in distinguishing biliary obstruction from other causes of jaundice, but failed to distinguish between extrahepatic and intrahepatic biliary obstruction. Serum glutamic oxalacetic transaminase and serum glutamic pyruvic transaminase estimations were performed in a number of cases, but were found to be of no value in the diagnosis of jaundice.

Cholestasis↗
PubMed1987

The quantitative estimation of diphtheria and tetanus toxoids. 1. The flocculation test and the Lf-unit.

Considerable confusion exist in the quantitative estimation of diphtheria and tetanus toxoids. The present paper is the first in a series of papers comparing various quantitative methods. It describes the flocculation test, gives a mathematical model for the three-dimensional reaction surface, and suggests different designs which facilitate the unbiased calculation of the end-point.

Analysis of Variance↗
PubMed1976

A re-evaluation of the slide flocculation test for the diagnosis of schistosomiasis with adult worms as antigen.

The present study was conducted to determine whether extracts from adult Schistosoma mansoni could be coated onto cholesterol-lecithin crystals. Of particular interest was the use of stunted schistosomes (SS) recovered from rabbits. The reactions obtained with this antigen in this slide flocculation (SF) test were compared with those employing antigens from cercariae and mature adult worms. The stunted schistosome SF test (SFSS) showed a high sensitivity and specificity while cercarial antigen showed extensive cross reaction with Trichinella spiralis, Ascaris lumbricoides, and Echinococcus granulosus antisera. Both SS and cercarial antigens reacted with syphilitic sera, but the former only with high titer sera. The antigen from mature adult worms could not be coated onto cholesterol crystals, a finding which is in agreement with previous investigations. The relative simplicity of the SFSS test and its apparent high sensitivity and specificity indicates that the test may be an ideal epidemiological tool for schistosomiasis surveys. The results obtained should encourage additional study of the procedure involved and investigation into the role of lipids in flocculation tests. In addition, the findings should stimulate immunological studies of the stunted schistosomes.

Animals↗
PubMed1975

Automation of a flocculation test for syphilis on Groupamatic equipment.

A flocculation reaction employing a cardiolipid antigen was used for syphilis screening on Groupamatic equipment in parallel with conventional screening reactions: Kolmer CF, RPCF, Kahn, Kline, and RPR. The positive samples were confirmed by FTA-200, FTA-ABS, TPI, and in some cases by TPHA. There were 5,212 known samples which had already been tested by all methods and of which 1,648 were positive, and 58,636 screened samples including 65 positives. Half of the samples in the first series were taken without anticoagulant; the remainder were collected in potassium EDTA. The percentage of false positives with the Groupamatic was about 1-4 per cent. The percentage of false negatives among positve (greater than or equal+) samples varied from 0-18 to 1-3 per cent.; on the other hand the sensitivity was less good for samples giving doubtful and/or dissociated reactions in conventional screening reactions. The specificity and sensitivity of this technique are acceptable for a blood transfusion centre. The reproducibility is excellent and the automatic reading of results accurate. Additional advantages are rapidity (340 samples processed per hour); simultaneous performance of eleven other immunohaematological reactions; no contamination between samples; automatic reading, interpretation, and print-out of results; and saving of time because samples are not filed sequentially and are automatically identified when the results are obtained. Although the importance of syphilis in blood transfusion seems small, estimates of the risk are difficult and further investigations are planned.

Autoanalysis↗
PubMed1970

Replacement of the international standard for tetanus antitoxin and the use of the standard in the flocculation test.

Since 1935 the International Unit for Tetanus Antitoxin has been defined as the activity contained in a certain weight of the first International Standard for Tetanus Antitoxin. As stocks of this standard had become depleted, 11 laboratories in 8 countries were requested to participate in a collaborative assay of a preparation proposed as a replacement.The assay results were analysed and presented to the WHO Expert Committee on Biological Standardization in 1969 which established the preparation studied as the second International Standard for Tetanus Antitoxin and defined the International Unit for Tetanus Antitoxin as the activity contained in 0.03384 mg of the second International Standard for Tetanus Antitoxin. This definition would ensure the continuity of the size of this international unit.The analysis of the collaborative studies also showed that the second International Standard for Tetanus Antitoxin has suitable properties for use in the flocculation test for the determination of the antigen content of tetanus toxoids in Lf values. The designation Lf-equivalent is described and the problems relating to the use of this term for the expression of results of in vitro assays are analysed in relation to the use of international units for expressing results of in vivo assays. As the second International Standard for Tetanus Antitoxin has an in vivo/in vitro ratio of 1.4, the Lf-equivalent of this antitoxin is 1.4 times less than its unitage.

Animals↗