DETERMINATION OF TENASCIN IN HUMAN SERUM BY THE USE OF A NEW ENZYME-IMMUNOASSAY

A sandwich-type enzyme immunoassay for tenascin (TN) was established by the use of two anti-human TN monoclonal antibodies and human TN produced by human melanoma cells as a standard. The assay system consists of polystyrene balls (6.5 mm in diameter) with immobilized first monoclonal antibody F(ab')2 fragments and the other antibody F(ab')2 fragments labeled with beta-D-galactosidase from Escherichia coli. The assay system has a minimum detectable sensitivity of 2 ng per assay tube, being sufficiently sensitive for the determination of serum TN concentrations with a satisfactory precision. Serum TN concentrations of healthy subjects were less than 2.0 mg per liter (n=29, mean +/- SD, 0.897 +/- 0.250 mg per liter) and those in sera of some patients with carcinoma were enhanced (n=47, mean +/- SD, 2.546 +/- 1.746 mg per liter).