ENZYME-IMMUNOASSAY FOR QUANTIFICATION OF TENASCIN IN BIOLOGIC SAMPLES

An enzyme immunoassay was developed for quantification of tenascin in biologic samples. An enzyme conjugate prepared by coupling peroxidase to a well-characterized, affinity-purified monoclonal antibody EB2 to human tenascin was used as principal reagent. The assay comprises 96-w ell microtitration strip plates with immobilized monoclonal antibody D B7 to human tenascin. By using a novel monoclonal antibody suppressing human-anti-mouse-factor, MAK33, in the sample buffer, the specificity of the test could be improved. The method has a minimum detectable se nsitivity of 1.5 ng tenascin and permits determination of tenascin in various biologic samples. The coefficients of variation within run and between run ranged from 0.9% to 5.0%. The average tenascin concentrat ion in normal plasma was 0.97 mg/L (n = 200) and in serum 0.73 mg/L (n = 200). The tenascin concentrations were also determined in samples o f urine, bile, amniotic fluid, seminal fluid, cerebrospinal fluid, bro nchoalveolar lavage (BAL) fluid, and pleural fluid showing general app licability of the assay. The method permits the determination of tenas cin in samples of different body fluids from various diseases, includi ng cancer, showing increased amounts of the protein at the tissue leve l.