Monoclonal Antibodies Application in Lateral Flow Immunochromatographic Assays for Drugs of Abuse Detection

Lateral flow assays (lateral flow immunoassays and nucleic acid lateral flow assays) have experienced a great boom in a wide variety of early diagnostic and screening applications. As opposed to conventional examinations (High Performance Liquid Chromatography, Polymerase Chain Reaction, Gas chromatography-Mass Spectrometry, etc.), they obtain the results of a sample’s analysis within a short period. In resource-limited areas, these tests must be simple, reliable, and inexpensive. In this review, we outline the production process of antibodies against drugs of abuse (such as heroin, amphetamine, benzodiazepines, cannabis, etc.), used in lateral flow immunoassays as revelation or detection molecules, with a focus on the components, the principles, the formats, and the mechanisms of reaction of these assays. Further, we report the monoclonal antibody advantages over the polyclonal ones used against drugs of abuse. The perspective on aptamer use for lateral flow assay development was also discussed as a possible alternative to antibodies in view of improving the limit of detection, sensitivity, and specificity of lateral flow assays.

Post-column reaction gas chromatography with a two-stage microreactor for the determination of volatile oxygenated compounds in high-pressure liquefied hydrocarbons

A reliable approach for the determination of volatile oxygenated compounds in high-pressure liquefied hydrocarbons with post-column reaction gas chromatography has been developed.

Catalase Reaction by Myoglobin Mutants and Native Catalase

The catalase reaction has been studied in detail by using myoglobin (Mb) mutants. Compound I of Mb mutants (Mb-I), a ferryl species (Fe(IV)=O) paired with a porphyrin radical cation, is readily prepared by the reaction with a nearly stoichiometric amount ofm-chloroperbenzoic acid. Upon the addition of H2O2to an Mb-I solution, Mb-I is reduced back to the ferric state without forming any intermediates. This indicates that Mb-I is capable of performing two-electron oxidation of H2O2(catalatic reaction). Gas chromatography-mass spectroscopy analysis of the evolved O2from a 50:50 mixture of H218O2/H216O2solution containing H64D or F43H/H64L Mb showed the formation of18O2(m/e= 36) and16O2(m/e= 32) but not16O18O (m/e= 34). This implies that O2is formed by two-electron oxidation of H2O2without breaking the O-O bond. Deuterium isotope effects on the catalatic reactions of Mb mutants and catalase suggest that the catalatic reactions ofMicrococcus lysodeikticuscatalase and F43H/H64L Mb proceed via an ionic mechanism with a small isotope effect of less than 4.0, since the distal histidine residue is located at a proper position to act as a general acid-base catalyst for the ionic reaction. In contrast, other Mb mutants such as H64X (Xis Ala, Ser, and Asp) and L29H/H64L Mb oxidize H2O2via a radical mechanism in which a hydrogen atom is abstracted by Mb-I with a large isotope effect in a range of 10–29, due to a lack of the general acid-base catalyst.