Development of a highly sensitive chemiluminescent assay for hydrogen peroxide under neutral conditions using acridinium ester and its application to an enzyme immunoassay.

We developed a highly sensitive chemiluminescent (CL) assay for hydrogen peroxide using 10-methyl-9-(phenoxycarbonyl) acridinium fluorosulfonate (PMAC) that produced chemiluminescence under neutral conditions and applied it to an enzyme immunoassay (EIA). One picomole of hydrogen peroxide could be detected using the optimized PMAC-CL method and 6.2 × 10(-20) mol β-D-galactosidase (β-gal) could be detected by combining an indoxyl derivative substrate and the proposed PMAC-CL method.

Evaluation of IgG ELISA using N-lauroyl-sarcosine-soluble proteins of Bartonella henselae for highly specific serodiagnosis of cat scratch disease.

Conventional IgG-ELISA methods for diagnosing cat scratch disease (CSD) caused by Bartonella hensela are still poor in sensitivity and specificity, which generally employ bacterial whole-cell proteins or N-lauroyl-sarcosine-insoluble proteins as the antigen. By Western blot analysis, we found that sarcosine-soluble fraction of proteins (SSP) showed highly specific reaction to immunofluorescence assay (IFA)-positive sera obtained from CSD patients compared with the above antigens. Clinical utility of the new ELISA employing SSP was evaluated using sera from 118 patients with clinically suspected CSD (sera positive by IFA: titers ≥ 1:256, n = 46; negative: titers <128, n = 72) and 88 sera from healthy individuals.