Development of a sensitive enzyme-linked immunosorbent assay for measurement of DNase I in human serum.

article i nfo Background: Serum deoxyribonucleaseI (DNase I)activity wasreported to increaseintheearly phaseafteronset of acute myocardial infarction (AMI). Up to now, DNase I activity has been quantified by the single radial enzyme diffusion (SRED) method, which unfortunately requires a long incubation time. Therefore it is necessary to develop another assay suitable for measurement of serum DNase I concentrations in a clinical setting. Methods: A sandwich ELISA was established for measurement of DNase I protein using a polyclonal antibody directedagainstDNaseIproteinandabiotinylatedmonoclonalforsubsequentdetection.Concentrationsofserum DNase I protein were measured in healthy individuals and patients with AMI. Results: Thismethod was as precise as SRED, and took less timethan SRED. A significant correlationwas observed between DNase I concentration and enzyme activity (r=0.839;Pb0.001). The average of serum DNase I in AMI patients within 0-12 h of chest pain was significantly higher than that in healthy individuals (Pb0.001), and decreased with time. Conclusions: We have developed a sensitive ELISA capable of measuring DNase I protein concentrations. This method may be a useful alternative to SRED as an aid to diagnosis of AMI based on the serum DNase I level.