We have been following with interest recent reports of false negative EMIT cannabinoid results (1,2). Our laboratory encountered similar problems in two New York City drug abuse proficiency survey samples. Samples 49N2 (February 1989) and 49T5 (August 1989) were spiked at 133 and 150 ng /mL respectively. Both yielded negative cannabinoid EMIT results when tested with the 100-ng/mL cutoff assay ...

Anti-nuclear antibodies (ANA) have traditionally been evaluated using indirect fluorescence assays (IFA) with HEp-2 cells. Quantitative immunoassays (EIA) have replaced the use of HEp-2 cells in some laboratories. Here, we evaluated ANA in 400 consecutive and unselected routinely referred patients using IFA and automated EIA techniques. The IFA results generated by two independent laboratories ...

Equatorial Africa has among the highest incidences of Kaposi's sarcoma (KS) in the world, thus earning the name "KS Belt." This was the case even before the HIV epidemic. To date, there is no clear evidence that HHV-8 seroprevalence is higher in this region but interpretation of the available literature is tempered by differences in serologic assays used across studies. We examined representati...

West Nile virus was introduced into the United States in 1999 and in only four seasons has become endemic east of the Rocky Mountains. Recently, immunoglobulin M (IgM)-capture enzyme immunoassays for the detection of West Nile virus-specific IgM and indirect IgG enzyme immunoassays for the detection of IgG antibodies against West Nile virus were made available from Focus Technologies and PANBIO...

Our experience with the determination of thyroxine (T4) in serum using a homogeneous enzyme immunoassay technique (EMIT, Syva Corp.) is reported. The intra-assay precision of the EMIT Manual Thyroxine Assay was investigated with 2 different calibrator concentrations and showed coefficients of variation varying from 5--2% for thyroxine concentrations of 40 and 120 micrograms/l thyroxine respecti...

Sixty-seven digoxin-containing sera were analyzed by both radioimmunoassay and EMIT. After some important modifications of the EMIT method, agreement between the two methods was very good. Reproducibility of the EMIT assay was excellent; daily variations in values found for control sera were quite small, and recovery of added digoxin was good. Slight hemolysis hadnegligible effects, but highly ...

A new homogeneous immunoassay (EMIT) for valproic acid was evaluated. Besides testing the manual version of this enzyme immunoassay, we also developed two mechanized procedures for centrifugal analyzers (the CentrifiChem and the COBAS system), which take less time and are more precise than the manual method. Within-assay precision (CV) was 4.5% with the manual technique and 2% with the analyzer...

A seasonal distribution was observed for rotaviruses in sewage by using indirect immunofluorescence. Levels were low from May through September and generally higher during winter and spring. In contrast, no seasonal pattern was observed for total enteroviruses. Limitations of the indirect immunofluorescence assay and enzyme immunoassay for environmental samples are discussed.

We describe the Ames Fluorescent Enzyme Immunoassay procedure for the detection of phenytoin in serum, and compare the results with it with those by enzyme immunoassay(EMIT), "high-pressure" liquid chromatography, and the Dupont aca. Sera from 48 patients who were receiving phenytoin were promptly analyzed in duplicate by EMIT, frozen, then assayed within four weeks by the other three methods. ...