[Immunoenzyme test system based on antibody F(ab)2-fragments for detecting the NP protein of the influenza virus].

A test system has been proposed for the detection of influenza A virus NP protein by solid-phase enzyme immunoassay in a modified system of "double" antibodies: the primary antibodies were F(ab)2-fragments of immunoglobulin class G isolated from rabbit antiserum specific for NP protein which was also used as the source of secondary antibodies. The antigen-bound antibodies were detected by protein A (from St. aureus) conjugate with horseradish peroxidase. The high specificity and sensitivity of the test system (0.3 ng/ml NP protein) and a minimal level of nonspecific reactions were demonstrated. The advantages of this method are discussed.