scholarly journals Bioluminescent Enzyme Immunoassay for the Detection of Norovirus Capsid Antigen

2012 ◽  
Vol 19 (12) ◽  
pp. 1949-1954 ◽  
Author(s):  
Nozomi Sakamaki ◽  
Yoshiyuki Ohiro ◽  
Mitsuki Ito ◽  
Mitsuru Makinodan ◽  
Tsubasa Ohta ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Fecal Sample ◽  
Recombinant Virus ◽  
Turnaround Time ◽  
Rapid Diagnosis ◽  
Analytical Sensitivity ◽  
Good Reproducibility ◽  
Reverse Transcription Pcr ◽  
Response Range ◽  
Coefficients Of Variation

ABSTRACTAn ultrasensitive and fully automated bioluminescent enzyme immunoassay (BLEIA) was developed for the detection of norovirus (NV) capsid antigen. In the evaluation tests with recombinant virus-like particles, the BLEIA demonstrated broad reactivity against several NV genotypes (genotypes 1, 3, 4, 7, 8, and 12 in genogroup I [GI] and genotypes 1, 2, 3, 4, 5, 6, 12, and 13 in GII), a wide dose-response range from 0.25 pg/ml to 10,000 pg/ml, and good reproducibility with low coefficients of variation (CVs) (within-run CVs of <2.8%, between-day CVs of <3.7%). In the evaluation tests with NV-positive fecal samples, a good correlation (y= 0.66x −3.21,r= 0.84) between the BLEIA and real-time quantitative reverse transcription-PCR was obtained. Furthermore, in the dilution test with NV specimens, the analytical sensitivity of NV was estimated to be 105to 106copies/g of fecal sample, indicating that the analytical sensitivity of the BLEIA is comparable to that of commercially available molecular methods. All assay steps are fully automated, the turnaround time is 46 min, and the throughput of the assay is 120 tests/h. These results indicate that the BLEIA is potentially useful for the rapid diagnosis of NV in epidemic and sporadic gastroenteritis.

Direct solid-phase enzyme immunoassay of progesterone in saliva.

1984 ◽  
Vol 30 (9) ◽  
pp. 1507-1511 ◽  
Author(s):  
D F Tallon ◽  
J P Gosling ◽  
P M Buckley ◽  
M M Dooley ◽  
W F Cleere ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Ovarian Function ◽  
Solid Phase ◽  
Turnaround Time ◽  
Plasma Progesterone ◽  
Coefficients Of Variation ◽  
High Concentrations ◽  
Working Day ◽  
Solid Phase Assay ◽  
Direct Solid

Abstract We have developed a rapid enzyme immunoassay for progesterone in saliva. This solid-phase assay is carried out on microtitre plates with no extraction or centrifugation steps. The detection limit of the assay is 200 fg per well (3.2 pmol/L). Intra- and interassay coefficients of variation for low, medium, and high concentrations of progesterone were 7.5, 16.0; 9.1, 8.3; and 8.7, 6.7%, respectively. Correlation between total plasma progesterone (assayed by enzyme immunoassay with extraction) and salivary progesterone concentrations was good (r = 0.848, p less than 0.001, n = 56). We found the assay useful for monitoring ovarian function. The analytical procedure is convenient, and one person can assay more than 200 saliva samples per working day. The turnaround time for 36 samples is 2 h, including 1.5 h of incubation time, when previously coated plates are used. We conclude that such assays are very suitable for measuring progesterone in serial saliva samples and could become the preferred method for monitoring ovarian function.

scholarly journals Analytical Evaluation of Visby Medical RT-PCR Portable Device for Rapid Detection of SARS-CoV-2

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 813
Author(s):  
Adriana Renzoni ◽  
Francisco Perez ◽  
Marie Thérèse Ngo Nsoga ◽  
Sabine Yerly ◽  
Erik Boehm ◽  
...  
Keyword(s):  
Point Of Care ◽  
Turnaround Time ◽  
Nucleic Acid Detection ◽  
Nasopharyngeal Swab ◽  
Analytical Sensitivity ◽  
Rt Pcr ◽  
Detection Systems ◽  
Reverse Transcription Pcr ◽  
Antigen Tests ◽  
Pcr Targeting

Extended community testing constitutes one of the main strategic pillars in controlling the COVID-19 pandemic. Reverse transcription PCR (RT-PCR) targeting the SARS-CoV-2 genome on nasopharyngeal swab samples is currently the reference test. While displaying excellent analytical sensitivity and specificity, this test is costly, often requires a substantial turnaround time, and, more importantly, is subject to reagent and other material shortages. To complement this technology, rapid antigen tests have been developed and made available worldwide, allowing cheap, quick, and decentralized SARS-CoV-2 testing. The main drawback of these tests is the reduced sensitivity when RT-PCR is the gold standard. In this study, we evaluate Visby an innovative, portable, easy-to-use RT-PCR point-of-care (POC) diagnostic device. Our retrospective analysis shows that overall, compared to the Cobas 6800 RT-qPCR assay (Roche), this RT-PCR POC technology detects SARS-CoV-2 RNA with 95% sensitivity (95%CI = 86.3–99%) and 100% specificity (95% CI = 80.5–100%). For samples with cycle-threshold values below 31, we observed 100% sensitivity (95% CI = 66.4–100%). While showing an analytical sensitivity slightly below that of a standard RT-qPCR system, the evaluated Visby RT-PCR POC device may prove to be an interesting diagnostic alternative in the COVID-19 pandemic, potentially combining the practical advantages of rapid antigen tests and the robust analytical performances of nucleic acid detection systems.

scholarly journals Evaluation of the performance of sysmex XN-3100 automated hematology analyzer regarding the sysmex XE-2100 and microscopic examination

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Said Incir ◽  
Kerim Erhan Palaoglu
Keyword(s):  
Comparative Method ◽  
Reference Method ◽  
Turnaround Time ◽  
Analytical Sensitivity ◽  
Biological Variability ◽  
Comparison Analysis ◽  
Blood Samples ◽  
Hematology Analyzer ◽  
Quality Control Materials ◽  
Automated Hematology Analyzer

AbstractObjectivesWe performed a verification study of the Sysmex XN-3100 hematology analyzer in comparison with the XE-2100 according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI) and the International Council for Standardization in Hematology (ICSH).Materials and methodsBlood samples and quality control materials were used for precision. For comparison, we used the current XE-2100 as the comparative method and analyzed 540 blood samples. The Passing-Bablok and Bland-Altman tests were performed according to the CLSI EP09-A3 and a carryover study was performed according to the CLSI H26-A2 guidelines. The flagging performance of the two analyzers was compared, using two experienced laboratory technicians as the reference method.ResultsThe Sysmex XN-3100 demonstrated high levels of precision for most parameters. For the comparison analysis, all parameters, except for MCHC, monocytes and basophils were within the systematic error limits of desirable biological variability criterion (SeDBV). The carryover was less than 0.4% for all parameters. The flagging performance of the XN-3100 was satisfactory and the overall efficiency was high.ConclusionsThe XN-3100 not only showed a strong correlation and agreement with the XE-2100 but also displayed a comparable analytical sensitivity, and increased specificity, which may result in an improved turnaround time and throughpu.

scholarly journals RS virus diagnosis: comparison of isolation, immunofluorescence and enzyme immunoassay

1986 ◽  
Vol 81 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Marilda M. Siqueira ◽  
Vanja Ferreira ◽  
Jussara P. Nascimento
Keyword(s):  
Tissue Culture ◽  
Respiratory Syncytial Virus ◽  
Enzyme Immunoassay ◽  
Bacterial Contamination ◽  
Virus Isolation ◽  
Rapid Diagnosis ◽  
Tissue Cultures ◽  
Virus Diagnosis ◽  
Under Five ◽  
Syncytial Virus

Two techniques for rapid diagnosis, immunofluorescence (IFAT) and enzyme immunoassay (EIA), have been compared with virus isolaion in tissue culture for the detection of respiratory syncytial virus (RSV) in specimens of nasopharyngeal secretions. The specimens were obtained from children under five years of age suffering from acute respiratory iliness, during a period of six months from January to June 1982. Of 471 specimens examined 54 (11.5%) were positive by virus isolation and 180 (38.2%) were positive by immunofluorescence. The bacterial contamination of inoculated tissue cultures unfortunately prevented the isolation of virus from many samples. Specimens from 216 children were tested to compare enzyme immunoassay and immunofluorescence. Of these 60 (27%) were positive by EIA and 121 (56%) were positive by IFAT. Our results suggest that the EIA technique although highly specific is rather insensitive. This may be because by the time these tests were done the originl nasopharyngeal secretions were considerably diluted and contained more mucus fragments than the call suspension used for IFAT. Of the three techniques, IFAT gives the best results although EIA may be useful where IFAT is not possible.

scholarly journals Evaluation of Coccidioides Antigen Detection in Dogs with Coccidioidomycosis

2012 ◽  
Vol 19 (3) ◽  
pp. 343-345 ◽  
Author(s):  
Emily J. Kirsch ◽  
Russell T. Greene ◽  
Annalisa Prahl ◽  
Stanley I. Rubin ◽  
Jane E. Sykes ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Fungal Infections ◽  
Rapid Diagnosis ◽  
Antigen Detection ◽  
Antibody Testing ◽  
Content Type ◽  
Healthy Dogs ◽  
Galactomannan Antigen ◽  
Antigen Antibody ◽  
Urine And Serum

ABSTRACTAntigen detection has been reported to be a promising method for rapid diagnosis of coccidioidomycosis in humans.Coccidioidesantigen detection has not been previously reported in dogs with coccidioidomycosis and was evaluated in 60 cases diagnosed based on detection of anti-Coccidioidesantibodies at titers of 1:16 or more in serum. Controls included dogs with presumed histoplasmosis or blastomycosis, other fungal infections, or nonfungal diseases and healthy dogs. Urine and serum specimens were tested using an enzyme immunoassay forCoccidioidesgalactomannan antigen. Antibody testing was performed at commercial veterinary reference laboratories. Antigen was detected in urine or serum of 12 of 60 (20.0%), urine only in 2 of 57 (3.5%), and serum only in 11 of 58 (19.0%) dogs with coccidioidomycosis. Antigen was detected in the urine of 3 of 43 (7.0%) and serum of 1 of 37 (2.7%) dogs with histoplasmosis or blastomycosis but not in 13 dogs with other fungal infections (serum, 9; urine, 13), 41 dogs with nonfungal diseases (urine, 41; serum, 18), or healthy dogs (serum, 21; urine, 21). Detection of antigen was an insensitive method for diagnosis of coccidioidomycosis in dogs in which the diagnosis was based primarily upon detection of antibodies at titers of 1:16 or higher, and the highest sensitivity was in serum.

Rapid diagnosis of enterovirus infection by a new one-step reverse transcription-PCR assay.

1997 ◽  
Vol 35 (4) ◽  
pp. 976-977 ◽  
Author(s):  
H H Kessler ◽  
B Santner ◽  
H Rabenau ◽  
A Berger ◽  
A Vince ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Rapid Diagnosis ◽  
Enterovirus Infection ◽  
Pcr Assay ◽  
Reverse Transcription Pcr ◽  
One Step

Enzyme immunoassay of free thyroxin in dried blood samples on filter paper.

1985 ◽  
Vol 31 (5) ◽  
pp. 750-753 ◽  
Author(s):  
N Hata ◽  
K Miyai ◽  
M Ito ◽  
Y Endo ◽  
Y Iijimi ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Filter Paper ◽  
Room Temperature ◽  
Normal Subjects ◽  
Blood Samples ◽  
Double Antibody ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Measurable Range

Abstract We describe a double-antibody enzyme immunoassay for determination of free thyroxin (FT4) in dried blood samples on filter paper, with use of a T4-beta-D-galactosidase complex. The measurable range of FT4 concentration in two 3-mm blood discs, each of which contained about 2.7 microL of blood, was 1.9 to 93 ng/L, as determined by comparison with concentrations of FT4 in known serum standards. FT4 in blood samples dried on filter paper was stable for at least four weeks when kept dry at -20 degrees C, room temperature, or 37 degrees C. The mean coefficients of variation were 7.6% (within assay) and 6.4% (between assays). Results for FT4 by this method correlated well with those for serum determined by radioimmunoassay (r = 0.98). The proposed method can be used to differentiate persons with hyper- and hypothyroidism from normal subjects and those with abnormal concentrations of thyroxin-binding globulin. The procedure seems suited for screening studies.

scholarly journals Enzyme Immunoassay for Measuring Aflatoxin B1 in Legal Cannabis

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 265 ◽  
Author(s):  
Fabio Di Nardo ◽  
Simone Cavalera ◽  
Claudio Baggiani ◽  
Matteo Chiarello ◽  
Marco Pazzi ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Aflatoxin B1 ◽  
Analytical Methods ◽  
Limit Of Detection ◽  
Direct Analysis ◽  
Aflatoxin Contamination ◽  
Throughput Capacity ◽  
Human Consumption ◽  
The European Union ◽  
Coefficients Of Variation

The diffusion of the legalization of cannabis for recreational, medicinal and nutraceutical uses requires the development of adequate analytical methods to assure the safety and security of such products. In particular, aflatoxins are considered to pose a major risk for the health of cannabis consumers. Among analytical methods that allows for adequate monitoring of food safety, immunoassays play a major role thanks to their cost-effectiveness, high-throughput capacity, simplicity and limited requirement for equipment and skilled operators. Therefore, a rapid and sensitive enzyme immunoassay has been adapted to measure the most hazardous aflatoxin B1 in cannabis products. The assay was acceptably accurate (recovery rate: 78–136%), reproducible (intra- and inter-assay means coefficients of variation 11.8% and 13.8%, respectively), and sensitive (limit of detection and range of quantification: 0.35 ng mL−1 and 0.4–2 ng mL−1, respectively corresponding to 7 ng g−1 and 8–40 ng g−1 ng g−1 in the plant) and provided results which agreed with a HPLC-MS/MS method for the direct analysis of aflatoxin B1 in cannabis inflorescence and leaves. In addition, the carcinogenic aflatoxin B1 was detected in 50% of the cannabis products analyzed (14 samples collected from small retails) at levels exceeding those admitted by the European Union in commodities intended for direct human consumption, thus envisaging the need for effective surveillance of aflatoxin contamination in legal cannabis.

Determination of Methyl 2-Benzimidazolecarbamate in Wine by Competitive Inhibition Enzyme Immunoassay

1993 ◽  
Vol 76 (4) ◽  
pp. 851-856 ◽  
Author(s):  
Rodney J Bushway ◽  
Lance R Paradis ◽  
Lewis B Perkins ◽  
Titan S Fan ◽  
Barbara E S Young ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Competitive Inhibition ◽  
White Wines ◽  
Average Recovery ◽  
Total Analysis Time ◽  
Coefficients Of Variation ◽  
Limit Of Quantitation ◽  
Total Analysis ◽  
Commercial Kit

Abstract A benomyl polyclonal enzyme immunoassay (EIA) commercial kit was used to quantitate methyl 2- benzimidazolecarbamate (MBC), a degradation product of benomyl in wine. Total analysis time, including sample preparation, was 30 min. As many as 8 samples can be analyzed simultaneously with a limit of quantitation of 5 ppb. The assay logarithmic response was linear from 0.4 to 26 ppb MBC. Intra-assay percent coefficients of variation (%CVs) ranged from 2.4 to 13 for standards and from 7.4 to 21 for actual wine samples. Interassay %CVs varied from 2.6 to 15 for the standards and from 6.9 to 23 for the samples. Average recovery from samples spiked at 10–10 000 ppb was 93% for evaporated red and white wines. MBC was determined in 134 different wines by immunoassay and liquid chromatography (LC). Of these samples, 98 were positive for MBC by both methods with a correlation coefficient (r) of 0.986. The other 36 samples had MBC levels that either were not detectable by either procedure or were below the 10 ppb limit of quantitation for LC. Concentrations of MBC in wine ranged from 5 to 1329 ppb, with the majority ranging from 10 to 300 ppb. Also, a mini-study was conducted using the plate EIA format.

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