Rapid Gas Chromatographic Assay of Diazinon:Application to the Study of Diazinon Kinetics in Rats

A rapid method was developed for the determination of diazinon in plasma using gas chromatography with electron-capture detection (GC-ECD). Following a single extraction with hexane from 100μl of plasma, diazinon was quantitated on a 3% OV-17 column. The detection limit was 10 ng/ml and linearity was obtained in the range of 25 ng/ml-2500 ng/ml.The applicability of the assay to single-dose kinetics in rats is illustrated

Rapid Detection of Escherichia coli by Electrochemical Assay of β-D-Galactosidase with p-Aminophenyl-β-D- Galactopyranoside as Substrate

An electrochemical assay was developed for β-D-galactosidase in coliform bacteria Escherichia coli (E. coli) using p-aminophenyl-β-D-galactopyranoside (PAPG) as substrate. The hydrolysis of PAPG by pure β-D-galactosidase was investigated based on the cyclic voltammetric (CV) behavior of p-aminophenyl (PAP). The results obtained using the pure enzyme showed that the addition of magnesium ion facilitated the enzyme-catalytic reaction. K m at the optimal magnesium ion concentration (5 mmol/L) was 0.90 mmol/L. The substrate was also used for coliformbacteria, where β-D-galactosidase in the bacteria cells was strongly induced by isopropyl-β-D-thiogalactopyranoside (IPTG). When the E. coli cell density exceeded 1.1×10 3 mL -1, the CV response was linearly related to the number of E. coli, the detection time was about one hour. This method can be developed into a portable biosensor for rapid assay of coliform bacteria.

Evaluation of a Rapid Immunochromatographic Middle East Respiratory Syndrome Coronavirus Antigen Detection Assay

Middle East respiratory syndrome coronavirus(MERS-CoV)infection in humans has a high mortality of>30%.Dromedaries are the reservoir of MERS-CoV and the main source of human infections.However,MERS-CoV infections in dromedaries are usually subclinical.Rapid diagnosis of MERS-CoV infection in these animals is important in preventing camel-to-human transmission of the virus.The possible cross-reactivity of a previously reported rapid nucleocapsid protein-based antigen detection assay for MERS-CoV was examined with different CoVs,including Tylonycteris bat CoV HKU4,dromedary camel CoV UAE-HKU23,human CoV-229E,human CoV-OC43,severe acute respiratory syndrome CoV-2 and rabbit CoV HKU14,where none of them showed false-positive results.The assay was further validated using quantitative real-time reverse transcription-polymerase chain reaction-confirmed MERS-CoV-positive and MERS-CoV-negative dromedary nasal samples collected in Dubai,the United Arab Emirates,which showed that the rapid antigen detection assay has a specificity of 100%and sensitivity of 91.7%.

A quantitative RT-PCR assay for rapid detection of Eurasianlineage H10 subtype influenza A virus

Dear Editor,Influenza A viruses(IAVs)are single-stranded,negative sense RNA viruses.IAV subtype is determined on the basis of the viral surface glycoproteins,hemagglutinin(HA),and neuraminidase(NA).To date,18 HA and 11NA subtypes have been reported(Tong et al.,2012).