Development of a monoclonal antibody-based sandwich-type enzyme-linked immunosorbent assay (ELISA) for detection of abrin in food samples.

Abrin is a plant toxin, which can be easily isolated from the seeds of Abrus precatorius. It may be used as a biological warfare agent. In order to detect abrin in food samples, a two-layer sandwich format enzyme-linked immunosorbent assay based on the monoclonal antibody (mAb) (as capture antibody) and rabbit polyclonal serum (as detecting antibody) was developed and applied for the determination of abrin in some food matrices.

Significance of Tyr302, His235 and Asp194 in the α-amylase from Bacillus licheniformis.

The calcium-binding residues, Tyr302 and His235, and the sodium-binding residue, Asp194, on the activity of Bacillus licheniformis α-amylase were investigated using site-directed mutagenesis. Tyr302 and His235 were replaced by Asn and Asp, respectively, to produce the mutants Y302N and H235D; Asp194 was replaced by Ala to produce D194A. The mutant amylases were purified to homogeneity; each was ~53 kDa.

An enhanced ELISA based on modified colloidal gold nanoparticles for the detection of Pb(II).

A novel probe based on colloidal gold nanoparticles (AuNPs) modified with goat anti-mouse IgG and horseradish peroxidase (HRP) was synthesized and an enhanced enzyme-linked immunosorbent assay (ELISA) based on the probe was developed. In the assay, the synthesized probe is bound with a monoclonal antibody (McAb) which is competitively bound by coated BSA-ITCBE-Pb(II) on plate and Pb(II) in samples. The HRP, used here for signal amplification catalytically oxidize the substrate and generate optical signals that is related to the concentration of Pb(II) and can be measured spectrophotometrically.

Development of a novel antibody probe useful for domoic acid detection.

The generation of monoclonal antibody (mAb) against marine toxins can serve as a valuable probe to detect this kind of compounds by immunological methods. However, traditional approaches to mAb generation usually need a comparative large quantity of standard substance (more than 400 microg mouse(-1)), and a comparative long immunization period (more than 6 weeks). Here we report a simple, inexpensive and fast protocol for the generation of monoclonal antibody probe specific for domoic acid (DA).

[Cloning and sequence analysis of major ampullate spidroin-1 partial cDNA from Araneus ventricosus].

In this paper, we successfully constructed the cDNA library of major ampullate gland of Araneus ventricousus using pUC18 vector and cloned the partial cDNA (AvMaSp1, GenBank accession number AY177203) encoding spider major ampullate gland spidroin-1 by means of picking colony randomly (Bird gun). The partial cDNA sequence of AvMaSp1 was 1 408 bp and its region in encoding was 1 288 bp. The protein deduced from AvMaSp1 contained 429 amino acid residues and molecular weight was 34.

Colloidal gold probe-based immunochromatographic assay for the rapid detection of brevetoxins in fishery product samples.

One-step immunochromatographic assay using colloidal gold-labeled monoclonal antibody (Mab) probe for the rapid detection of brevetoxins (PbTxs) in fishery product samples was developed. The described assay was based on a competitive format using two antibodies. The primary antibody was conjugated with colloidal gold (detector reagent), the secondary antibody (capture reagent) was immobilized within a defined detection zone (control line) on a diagnostic cellulose nitrate membrane.