Chemiluminescent immunoassay (CLIA) for the detection of brucellosis and tularaemia antigens.

The detection of brucellosis and tularaemia infection agents is of particular interest for medical practice. The possibility of using enhanced chemiluminescence reactions for the determination of these agents is studied in this work. Light intensity depends on both the conjugate concentration used and the conditions at which the adsorption was performed. Optimal conditions for these test-systems were: approximately 20 micrograms/mL of Ig and 200 micrograms/mL (titre 1:20) of conjugate. As is seen from the chemiluminescent and spectrophotometric results the lowest determined concentrations are 10 and 30 ng/mL (for brucellosis) and 1 and 5 ng/mL (for tularaemia), respectively. Calibration curves in the antigen concentrations ranging from 10 to 2500 ng/mL (for brucellosis) and from 1 to 500 ng/mL (for tularaemia) are observed. Optical density depends linearly on the logarithm of the antigen concentration from 30 to 5000 ng/mL (for brucellosis) and from 5 to 250 ng/mL (for tularaemia). The results obtained permit the conclusion that the chemiluminescence method can be used in enzyme immunoanalysis for brucellosis and tularaemia antigens.

Chemiluminescence ELISA for the detection of antibodies to bovine leukaemia virus antigens.

A chemiluminescence enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to bovine leukaemia virus antigens (BLV) has been developed. The possibility of using an enhanced chemiluminescence reaction for the determination of adsorbed immunoperoxidase conjugates was studied in this work. The intensity of chemiluminescence depends on both the concentration of reagents and experimental conditions used. The efficiency of the assay is determined by the formation of an immobilized antigen monolayer. A relationship between the quantity of the protein added and adsorbed has been shown. The optimal time and temperature for the antigen-antibody incubation steps have been estimated for each system (3 h at 37 degrees C was chosen as a standard incubation time). A linear dependence of the chemiluminescence intensity and optical density on the concentration of antibodies to the BLV antigens was observed. The detection limit of antibodies in the chemiluminescence ELISA is 2-3 times lower than that in the spectrophotometric one. The results obtained indicate the possibility of using both methods.

[The comparative evaluation of spectrophotometric and chemiluminescent detection in an immunoenzyme test of antibodies to the antigens of the bovine leukosis virus]. / Sravnitel'naia otsenka spektrofotometricheskogo i khemiliuminestsentnogo detektirovaniia v immunofermentnom teste antitel k antigenam virusa leikoza krupnogo rogatogo skota.

Comparative evaluation of the sensitivity limit in the detection of antibodies to bovine leukemia virus in the enzyme immunoassay with the use of chemiluminescent and spectrophotometric detection techniques was carried out. In this assay 3-amino-1,4-phthalazinedion was used as chemiluminescent substrate and ortho-phenylenediamine, as chromogenic substrate. The chemiluminescent signal was registered by means of a special luminometer designed at the Institute of Biochemistry (Lithuanian Acad. Sci.). The use of the chemiluminescent substrate permitted the detection of proteins in amounts 2-3 times lower than those detected by the spectrophotometric technique.