Autoantibodies - enemies, and/or potential allies?

Autoantibodies are well known as potentially highly harmful antibodies which attack the host binding to self-antigens, thus causing severe associated diseases and symptoms (e.g. autoimmune diseases).

Antibody Purification Using Affinity Chromatography.

Antibodies are an integral part of many biological assays and biotherapeutics. However, the sources from which antibodies are derived frequently contain other contaminants which may interfere with assays or cause adverse reactions if administered in vivo. Therefore, a means of isolating these antibodies from their source at high levels of purity is critical.

Design and fabrication of a low-cost wireless camera imaging system for centrifugal microfluidics.

Centrifugal microfluidic devices offer a robust method for low-volume fluid handling by combining low-cost instrumentation with highly integrated automation. Crucial to the efficacy of Lab-on-a-Disc (LoaD) device operation is the selection of robust valving technology, the design of on-disc fluidic structures, and accurate control of disc spin-speeds (centrifugal force) during operation. The design and refinement of fluidic and valving structures is often guided by inspecting disc operation using high-speed camera systems.

A one-step reverse transcription recombinase polymerase amplification assay for lateral flow-based visual detection of PVY.

Potato virus Y (PVY) is an abundant and damaging virus which reduces crop yield and marketability. Accurate detection of this economically important virus both in-field and in seed potatoes is considered essential in the control of PVY spread. Current detection methods are focused on immunodetection and PCR-based methods, however, identification of PVY through isothermal amplification is a promising avenue for developing accessible, on-site diagnostics with quick turnaround times.

Generation, selection and modification of anti-cardiac troponin I antibodies with high specificity and affinity.

Current diagnosis of acute myocardial infarction involves quantification of circulating cTn levels. This work endeavoured to generate and enhance recombinant antibody fragments targeting various epitopes on the N- and C-terminals of the cTnI molecule, thereby facilitating highly sensitive detection of the troponin molecule. From this approach, two anti-cTnI scFv antibodies were successfully selected using either phage display or structural reformatting of full length anti-cTnI IgG.

Binding Characteristic of Various Antibody Formats Against Aflatoxins.

The application of recombinant antibodies for the analysis of foods and food contaminants is now a major focus, given their capacity to be engineered to tailor their specificity, enhance their stability, and modify their structural formats to fit the desired analytical platform. In this study, human scFv antibody fragments generated against aflatoxin B1 (AFB1) were selected as the model antibody to explore the effect of antibody formats on their binding activity and to evaluate their potential use as immunoreagents for food contaminant analysis. Four human scFv antibody fragments against aflatoxin B1 (AFB1), previously isolated and engineered by chain shuffling, were converted into various formats, that is, scFv-AP fusions, scFv-Fc, and whole IgG molecules.

Advances in point-of-care testing for cardiovascular diseases.

Point-of-care testing (POCT) is a specific format of diagnostic testing that is conducted without accompanying infrastructure or sophisticated instrumentation. Traditionally, such rapid sample-to-answer assays provide inferior analytical performances to their laboratory counterparts when measuring cardiac biomarkers. Hence, their potentially broad applicability is somewhat bound by their inability to detect clinically relevant concentrations of cardiac troponin (cTn) in the early stages of myocardial injury.

The role of antibody-based troponin detection in cardiovascular disease: A critical assessment.

Cardiovascular disease has remained the world's biggest killer for 30 years. To aid in the diagnosis and prognosis of patients suffering cardiovascular-related disease accurate detection methods are essential. For over 20 years, the cardiac-specific troponins, I (cTnI) and T (cTnT), have acted as sensitive and specific biomarkers to assist in the diagnosis of various types of heart diseases.

Glycosylation in Indolent, Significant and Aggressive Prostate Cancer by Automated High-Throughput -Glycan Profiling.

The diagnosis and treatment of prostate cancer (PCa) is a major health-care concern worldwide. This cancer can manifest itself in many distinct forms and the transition from clinically indolent PCa to the more invasive aggressive form remains poorly understood. It is now universally accepted that glycan expression patterns change with the cellular modifications that accompany the onset of tumorigenesis.

Antibody stability: A key to performance - Analysis, influences and improvement.

An antibody's stability greatly influences its performance (i.e. its specificity and affinity).

Understanding microcystin-LR antibody binding interactions using in silico docking and in vitro mutagenesis.

Microcystins (MCs) are a group of highly potent cyanotoxins that are becoming more widely distributed due to increased global temperatures and climate change. Microcystin-leucine-arginine (MC-LR) is the most potent and most common variant, with a guideline limit of 1 μg/l in drinking water. We previously developed a novel avian single-chain fragment variable (scFv), designated 2G1, for use in an optical-planar waveguide detection system for microcystin determination.

Cardiac Troponin I: Ultrasensitive Detection Using Faradaic Electrochemical Impedance.

An electrochemical biosensor for the detection of cardiac troponin I, cTnI, an important cardiac biomarker, is described. A combination of a novel monoclonal antibody, mAb20B3, and a novel Ir(III)-based metal complex was used for detection using faradaic electrochemical impedance spectroscopy. A limit of detection of 10 ag/mL was achieved, which is significantly lower than established assays.

Evaluation of Molecularly Imprinted Polymers for Point-of-Care Testing for Cardiovascular Disease.

Molecular imprinting is a rapidly growing area of interest involving the synthesis of artificial recognition elements that enable the separation of analyte from a sample matrix and its determination. Traditionally, this approach can be successfully applied to small analyte (<1.5 kDa) separation/ extraction, but, more recently it is finding utility in biomimetic sensors.

Sowing seeds for the future: The need for on-site plant diagnostics.

Point-of-care technology is a term used to describe any treatment given at the "site-of-need". The span of point-of-care has broadened, growing from its current dominant usage in clinical settings to encompass many sectors, such as water and food testing. This review focuses on applications of point-of-care/use technology in phytodiagnostics, a field which requires accurate diagnostic systems with increasing urgency due to the demands of global food needs in conjunction with persistent crop loss due to pathogens and increased awareness of the environmental impacts of extensive agrochemical usage.

Point-of-Care Compatibility of Ultra-Sensitive Detection Techniques for the Cardiac Biomarker Troponin I-Challenges and Potential Value.

Cardiac biomarkers are frequently measured to provide guidance on the well-being of a patient in relation to cardiac health with many assays having been developed and widely utilised in clinical assessment. Effectively treating and managing cardiovascular disease (CVD) relies on swiftly responding to signs of cardiac symptoms, thus providing a basis for enhanced patient management and an overall better health outcome. Ultra-sensitive cardiac biomarker detection techniques play a pivotal role in improving the diagnostic capacity of an assay and thus enabling a better-informed decision.

Unravelling enhancement of antibody fragment stability - Role of format structure and cysteine modification.

Antibody-based diagnostics and therapeutics have huge commercial value. However, applications of antibodies are often limited by instability, particularly for recombinant antibody formats. This paper describes the conversion of a single-chain variable fragment (scFv) antibody to a single-chain antibody fragment (scAb) with notably improved stability characteristics.

Measurement of the IgM and IgG Autoantibody Immune Responses in Human Serum has High Predictive Value for the Presence of Colorectal Cancer.

Introduction: Colorectal cancer is a major public health issue, with incidences continuing to rise owing to the growing and aging world population. Current screening strategies for colorectal cancer diagnosis suffer from various limitations, including invasiveness and poor uptake. Consequently, there is an unmet clinical need for a minimally invasive, sensitive, and specific method for detecting the presence of colorectal cancer and pre-malignant lesions.

Enhancing recombinant antibody performance by optimally engineering its format.

Antibody-based sensors are now widely used in therapeutics, diagnostics, and in environmental monitoring. Recombinant antibodies are becoming integral parts of such devices due to their reported high affinities, their capacity for engineering to achieve highly defined performance characteristics and the fact that their production can be optimized to a significant degree. To aid as a model for the identification of important analyte binding residues within the antibody sub-structure and elucidate the docking characteristics of small molecules such as metabolites, illicit drugs, biotherapeutics (proteins, peptides and nucleic acids) or toxins towards the antibody, herein we report the binding of the harmful cyanobacterial-toxin, microcystin-leucine-arginine (MC-LR) to a single chain fragment variable (scFv) antibody fragment.

An Innovative Portable Biosensor System for the Rapid Detection of Freshwater Cyanobacterial Algal Bloom Toxins.

Harmful algal blooms in freshwater systems are increasingly common and present threats to drinking water systems, recreational waters, and ecosystems. A highly innovative simple to use, portable biosensor system (MBio) for the rapid and simultaneous detection of multiple cyanobacterial toxins in freshwater is demonstrated. The system utilizes a novel planar waveguide optical sensor that delivers quantitative fluorescent competitive immunoassay results in a disposable cartridge.

Measuring Antibody-Antigen Binding Kinetics Using Surface Plasmon Resonance.

Surface plasmon resonance (SPR) is now widely embraced as a technology for monitoring a diverse range of protein-protein interactions and is considered almost de rigueur for characterizing antibody-antigen interactions. The technique obviates the need to label either of the interacting species, and the binding event is visualized in real time. Thus, it is ideally suited for screening crude, unpurified antibody samples that dominate early candidate panels following antibody selection campaigns.

Direct immunoassays and their performance - theoretical modelling of the effects of antibody orientation and associated kinetics.

The orientation and activity of antibodies immobilized on solid surfaces are of direct relevance to many immunosensing applications. We therefore investigate a mathematical model which estimates the fraction of antibodies which are available for reaction in a randomly adsorbed sample. Numerical simulations are presented which highlight the separate effects of antibody orientation, accessibility and loss of binding ability on the amount of captured antigen.

Novel Microfluidic Analytical Sensing Platform for the Simultaneous Detection of Three Algal Toxins in Water.

Globally, the need for "on-site" algal-toxin monitoring has become increasingly urgent due to the amplified demand for fresh-water and for safe, "toxin-free" shellfish and fish stocks. Herein, we describe the first reported, Lab-On-A-Disc (LOAD) based-platform developed to detect microcystin levels in situ, with initial detectability of saxitoxin and domoic acid also reported. Using recombinant antibody technology, the LOAD platform combines immunofluorescence with centrifugally driven microfluidic liquid handling to achieve a next-generation disposable device capable of multianalyte sampling.

Integrating biomarkers across omic platforms: an approach to improve stratification of patients with indolent and aggressive prostate cancer.

Classifying indolent prostate cancer represents a significant clinical challenge. We investigated whether integrating data from different omic platforms could identify a biomarker panel with improved performance compared to individual platforms alone. DNA methylation, transcripts, protein and glycosylation biomarkers were assessed in a single cohort of patients treated by radical prostatectomy.

Developments in Point-of-Care Diagnostic Technology for Cancer Detection.

Cancer is the cause of death for one in seven individuals worldwide. It is widely acknowledged that screening and early diagnosis are of vital importance for improving the likelihood of recovery. However, given the costly, time-consuming, and invasive nature of the many methods currently in use, patients often do not take advantage of the services available to them.

Enhancement and Analysis of Human Antiaflatoxin B1 (AFB1) scFv Antibody-Ligand Interaction Using Chain Shuffling.

A human antiaflatoxin B1 (AFB1) scFv antibody (yAFB1-c3), selected from a naı̈ve human phage-displayed scFv library, was used as a template for improving and analysis of antibody-ligand interactions using the chain-shuffling technique. The variable-heavy and variable-light (VH/VL)-shuffled library was constructed from the VH of 25 preselected clones recombined with the VL of yAFB1-c3 and vice versa. Affinity selection from these libraries demonstrated that the VH domain played an important role in the binding of scFv to free AFB1.