Biosensor characterization of antigenic site A of foot-and-mouth disease virus presented in different vector systems

A Brief Review on Diagnosis of Foot-and-Mouth Disease of Livestock: Conventional to Molecular Tools

Foot-and-mouth disease (FMD) is one of the highly contagious diseases of domestic animals. Effective control of this disease needs sensitive, specific, and quick diagnostic tools at each tier of control strategy. In this paper we have outlined various diagnostic approaches from old to new generation in a nutshell. Presently FMD diagnosis is being carried out using techniques such as Virus Isolation (VI), Sandwich-ELISA (S-ELISA), Liquid-Phase Blocking ELISA (LPBE), Multiplex-PCR (m-PCR), and indirect ELISA (DIVA), and real time-PCR can be used for detection of antibody against nonstructural proteins. Nucleotide sequencing for serotyping, microarray as well as recombinant antigen-based detection, biosensor, phage display, and nucleic-acid-based diagnostic are on the way for rapid and specific detection of FMDV. Various pen side tests, namely, lateral flow, RT-LAMP, Immunostrip tests, and so forth. are also developed for detection of the virus in field condition.

Discriminating foot-and-mouth disease virus-infected and vaccinated animals by use of beta-galactosidase allosteric biosensors

Recombinant beta-galactosidases accommodating one or two different peptides from the foot-and-mouth disease virus (FMDV) nonstructural protein 3B per enzyme monomer showed a drastic enzymatic activity reduction, which mainly affected proteins with double insertions. Recombinant beta-galactosidases were enzymatically reactivated by 3B-specific murine monoclonal and rabbit polyclonal antibodies. Interestingly, these recombinant beta-galactosidases, particularly those including one copy of each of the two 3B sequences, were efficiently reactivated by sera from infected pigs. We found reaction conditions that allowed differentiation between sera of FMDV-infected pigs, cattle, and sheep and those of naïve and conventionally vaccinated animals. These FMDV infection-specific biosensors can provide an effective and versatile alternative for the serological distinction of FMDV-infected animals.

Survey of the 1998 optical biosensor literature

The utilization of optical biosensors to study molecular interactions continues to expand. In 1998, 384 articles relating to the use of commercial biosensors were published in 130 different journals. While significant strides in new applications and methodology were made, a majority of the biosensor literature is of rather poor quality. Basic information about experimental conditions is often not presented and many publications fail to display the experimental data, bringing into question the credibility of the results. This review provides suggestions on how to collect, analyze and report biosensor data.

Active concentration measurements of recombinant biomolecules using biosensor technology

Whereas the concentration of a biomolecule simply refers to the amount of chemical substance per unit of volume, its active concentration refers to a relational parameter that has meaning only with respect to the molecule's ability to interact specifically with one particular ligand. When proteins are studied in a biological context, it is the biologically active concentration that is relevant, and not the total concentration of correctly and incorrectly folded molecules. Using a biosensor instrument the concentration of active biomolecules in a preparation can be measured by injecting the preparation at different flow rates onto a sensor chip surface presenting a high concentration of a specific ligand. The method can be used under conditions of partial mass transport limitation and does not require a pre-established standard curve. When the method was used to measure the active concentration of several recombinant proteins it was found that the active concentration was much lower than the nominal concentration determined by conventional methods. The active concentration also depended on the ligand used in the binding assay, reflecting the fact that active concentration can only be defined with respect to one specific probe. Such discrepancies in concentration values, if undetected, may lead to erroneous conclusions regarding the properties and behaviour of recombinant proteins tested in different assays.