Heated histoplasmin as a control for non-specificity in the complement fixation test for histoplasmosis

We present data in support of the use of a heated histoplasmin control for the complement fixation (CF) test for histoplasmosis to assist in the detection of the presence of h or m antibody.     

Fluorescent antibody method

Гыл синтезирован флюоресцентный краситель 1-диметиламинонафтален-5-суляфонил-хлорид и исследовались условия его коньюгации с белка.ми. Концентрация белков и ионная сила раствора в реакцcии не оказывали суцественного влияния на интенсивность связывания, тогда как деиствие pH было противоположным. При всех опытах приименялся одии вид гамма-глобулина, иммунологические свойства которого в результате химической интеракции с данзилхлоридом не менялися. С 1 молекулой гамма-глобулина связывались—В в зависимости от условий опыта—3—9 молекул флюооресцирующего красителя. При длительном отстаивании комплекса белки-краситель при +4° C на-блюдалась неболящая диссоциация, которая не имела существенного влияния на красяцую способностя кончюгата.     

Fluorescent antibody method

Был разработан спектрофотометрический метод количественного определения белка и 1-диметиламинонафтален-5-сульфоновой кислоты в флюоресцентных антителах. Выяснилось, что после основательного диализа коньюгаты не содержат свободного красителя, который был бы помехой определений. В зависимости от условий коньюгации среднее отношение веса белка к флюоресцентному красителю в меченом γ-глобулине составляло 76–245, что отвечает 3–9 молекулам красителя, связанным с 1 молекулой глобулина.     

Reiter protein complement fixation test; a preliminary comparison of the TPI test with the complement fixation test employing a soluble protein antigen derived from the Reiter strain

A comparative study of the specificity of the Reiter protein complement fixation (RPCF) test and the Treponema pallidum immobilization (TPI) test on 180 sera showed that the results in 178 instances or 98.9 per cent were in agreement. The sensitivity of the RPCF test, when compared to the TPI test, on 189 sera from patients known to have syphilis was in agreement in 182 or 96.3 per cent, assuming a correlation exists between positive TPI and both the "reactive" or "weakly reactive" RPCF test results. As to reproducibility of results, the RPCF test results agreed in 84 of the 87 sera tested (95.4 per cent). The sera were tested at least three times on different days. Anticomplementary reactions were observed in three of 91 normal sera.     

Antibody estimation by indirect complement fixation test for foot-and-mouth disease in cattle.

Antibody against foot-and-mouth disease (FMD) virus was measured by the indirect complement fixation (ICF) test. For this test serum samples were collected from cattle experimentally infected with FMD virus of O, A and Asia 1 types, as well as cattle infected in the field. Two types of antigen were used. One was antigen derived from infected lingual epithelial culture prepared by Frenkel's method with each type of the virus. The other was antigen derived from the lingual epithelium of cattle infected by virus inoculation. ICF antibody began to be dectected about 4 5 days after inoculation. It reached a maximum titer 10 14 days after inoculation, remaining at this titer for about a week or two, and then decreased gradually. It was, however, detectable even 63 days after inoculation. The rise and fall of ICF antibody was parallel with that of neutralizing antibody, although that antibody was always lower in titer than this. ICF antibody was detected type-specifically from cattle infected experimentally and naturally. These results indicated that the ICF test was available for the routine serological diagnosis and epizootiological investigation and research.     

Inactivated-concentrated virus antigen for indirect complement fixation test of foot-and-mouth disease.

To the culture fluids of BHK-21 cells infected with each of types O, A, and Asia 1 of foot-and-mouth disease virus was added acetylethyleneimine to 0.05% (v/v). The mixtures were incubated at 37 degrees C for 24 hours. To them were then added polyethylene glycol 6000 to 10% (w/v), and the mixtures concentrated to one-tenth of the initial volume. The resulting inactivated-concentrated virus antigens showed a complement fixation (CF) titer ranging from 12 to 24. The recovery rate of CF activity was 40 approximately 60%. This activity of each antigen was maintained at 4 degrees C or -70 degrees C for 6 months at least. Experimentally infected cattle were examined for the development of antibody by the aid of the indirect complement fixation (ICF) test with those antigens. As a result, ICF antibody began to be detected 3 approximately 5 days after inoculation. Its titer reached a maximum 10 approximately 14 days after inoculation and decreased gradually thereafter. It was detected even 232 days after inoculation. There was a tendency for the development of ICF antibody to be parallel with that of neutralizing antibody. It was suggested that ICF antibody might be type-specific. In conclusion, the antigens prepared had such high activity that they could be used for the determination of antibody by ICF. In addition, they were of great practical value because of their sufficient keeping quality and safety.