[Immunoenzyme method of determining Pseudomonas aeruginosa exotoxin A by using a conjugate of beta-lactamase with specific antibodies].

Specific antibodies for immunoenzymatic assay of P. aeruginosa exotoxin A were isolated with affinity chromatography on exotoxin A-Sepharose 4B. A conjugate of the antibodies to exotoxin A with beta-lactamase from Bacillus licheniformis 749/c was prepared by linking glutaric aldehydes. The conjugate showed high immunospecific and enzymatic activity and was used for competitive solid phase immunoenzymatic assay. Sensitivity of the assay provided determination of exotoxin A in concentration of 20 ng/ml. It was used for determining P. aeruginosa exotoxin A in culture fluids.