Rabies Diagnosis: Fluorescent Antibody Technique

Contrary to some conclusions of the lay public, rabies still constitutes a major problem to human and animal welfare. In fact in the last four or five years there has been somewhat of an increase in the incidence of rabies. The veterinarian serves a most important role in the control of rabies

Fluorescent antibody detection of microorganisms in terrestrial environments

The fluorescent antibody technique and its use in direct microscopic examination of the soil is discussed. Feasibility analyses were made to determine if the method could be used to simultaneously observe and recognize microorganisms in the soil. Some data indicate this may be possible. Data are also given on two related problems involving the interaction of soil microorganisms with plant roots to form symbiotic structures. One was concerned with the developmental ecology and biology of the root nodule of alder and the second was concerned with the ectotrophic mycorrhizal structure on forest trees, especially pines. In both, the fluorescent antibody detection of the microbial symbiont both as a free living form in soil, and as a root inhabiting form in the higher plant was emphasized. A third aspect of the research involved the detection of autotrophic ammonia oxidizing microorganisms in soil

Fluorescent humanized anti-CEA antibody specifically labels metastatic pancreatic cancer in a patient-derived orthotopic xenograft (PDOX) mouse model.

Pancreatic cancer is a highly lethal disease in part due to incomplete tumor resection. Targeting by tumor-specific antibodies conjugated with a fluorescent label can result in selective labeling of cancer in vivo for surgical navigation. In the present study, we describe a patient-derived orthotopic xenograft model of pancreatic cancer that recapitulated the disease on a gross and microscopic level, along with physiologic clinical manifestations. We additionally show that the use of an anti-CEA antibody conjugated to the near-infrared (NIR) fluorescent dye, IRDye800CW, can selectively highlight the pancreatic cancer and its metastases in this model with a tumor-to-background ratio of 3.5 (SEM 0.9). The present results demonstrate the clinical potential of this labeling technique for fluorescence-guided surgery of pancreatic cancer

In Vivo Fluorescence Imaging of E-Selectin: Quantitative Detection of Endothelial Activation in Arthritis

Rheumatoid arthritis (RA) is a chronic progressive systemic inflammatory disease, characterized by synovial inflammation and localized destruction of cartilage and bone. Heterogeneity in the clinical presentation of RA and uncertainty about which patients will respond to treatment makes diagnosis and management challenging. Fluorescent imaging in the near infrared (NIR) spectrum significantly decreases tissue autofluorescence offering unique potential to detect specific molecular targets in vivo. E-selectin or endothelial adhesion molecule-1 (ELAM-1), a 115kDa glycoprotein induced on endothelial cells in response to pro-inflammatory cytokines involved in RA, such as interleukin (IL)-1 beta and tumour necrosis factor alpha (TNF alpha). E-selectin has been well validated as a potential biomarker of disease activity. My study aimed to investigate whether E-selectin targeted optical imaging in vivo could be developed as a sensitive, specific and quantifiable preclinical molecular imaging technique, and also whether this approach could be used to delineate the molecular effects of novel therapies. I utilised anti-E-selectin antibody labelled with NIR fluorophore in a mouse model of paw swelling induced by intra-plantar injection of TNF alpha, and in acute collagen-induced arthritis (CIA) in DBA/1 mice, a widely used model of RA. E-selectin generated signal, localised to points of maximal clinical inflammation in the inflamed mouse paw in both models with significant differences to control antibody. Binding of anti-E-selectin antibody was also demonstrated by immunohistochemistry in both models. The ability of E-selectin targeted imaging to detect sub-clinical endothelial activation was also investigated, demonstrating that E-selectin may be an excellent way of determining subclinical vascular activation in CIA. Finally the effect of novel targeted therapy – RB200 which blocks epidermal growth factor (EGF) signalling was investigated. This demonstrated that E-selectin targeted signal could be absolutely abrogated to a level seen in unimmunised healthy control animals, following combination treatment with RB200 and the TNF alpha inhibitor etanercept. E-selectin targeted optical imaging is a viable in vivo imaging technique that can also be applied to quantify disease and investigate the effects of novel molecular therapies. It holds significant promise as a molecular imaging technique for future translation into the clinic for patients with rheumatoid arthritis and other inflammatory diseases

Rapid Identification of Streptococcal Infections Using Fluorescent Antibody Techniques

The use of fluorescent microscopy coupled with immunological techniques offer new methods for the demonstration of antigen-antibody reactions. The adaptation of these techniques to grouping of beta hemolytic streptococci makes feasible their further adaptation toward identification of group A streptococci in clinical material. Commercially available labeled antibodies against group A beta hemolytic streptococci were obtained for use in this study. A method for the determination of labeled antisera specificity is proposed and a technique for absorbing out any heterologous reacting antibody is described. Using this commercial labeled antisera, subsequent to specificity studies plus absorption if necessary, adaptations of basic fluorescent antibody techniques are suggested for the rapid diagnosis of clinical group A beta hemoytic streptococci infections

Indirect Fluorescent Antibody Technique based Prevalence of Surra in Equines

This project was carried out to find the prevalence of trypanosomiasis in equine in District Gujranwala by using indirect fluorescent antibody technique and thin smear method. Blood samples were collected from a total of 200 horses and donkeys of different ages and either sex. Duplicate thin blood smears were prepared from each sample and remaining blood samples were centrifuged to separate the serum. Smears from each animal were processed for giemsa staining and indirect fluorescent antibody test (IFAT). Giemsa stained smears revealed Trypanosome infection in 4/200 (2.0%) samples and IFAT in 12/200 (6.0%) animals

Tropomyosin antibody: the specific localization of tropomyosin in nonmuscle cells

An antibody against purified chicken skeletal muscle tropomyosin is used in indirect immunofluorescence to visualize the localization of tropomyosin in a variety of nonmuscle cells. The antibody produces a fluorescent pattern which is very similar to that obtained with an actin-specific antibody. This pattern is composed of fluorescent fibers which are shown to be coincident with the fibers seen with phase-contrast optics. High resolution epifluorescent microscopy reveals that fibers stained with the actin antibody show a continuous fluorescence, while fibers reacted with the tropomyosin antibody show a periodic fluorescence. Measurements indicate that the lengths of the fluorescent segments are variable with an average of 1.2 μm while the spacing between segments is approximately 0.4 μm

Aqueous synthesis of CdTe quantum dot as biological fluorescent probe for monitoring methyl parathion by fluoro-immunosensor

Bioconjugation of quantum dots (QDs) provide high resolution in biological fluorescent labelling as a result of physical and optical properties of QDs. This intrinsic property of QDs can be made use of for sensitive detection of target analytes including food and environmental monitoring. In this investigation, we report the bioconjugation of thiol stabilized CdTe QD for the sensitive detection of methyl parathion (MP) at picogram level. The specificity in the analysis was attributed by highly specific competitive immunological reactions between free MP and CdTe QD bioconjugated MP (MP-BSA-CdTe) for immobilized anti-MP IgY antibodies in a simple flow injection system. We also report the possible resonance energy transfer phenomenon as a result of nanobiomolecular interaction obtained through the bioconjugation of CdTe QD with protein bovine serum albumin (BSA). This has resulted in a significant change in the photo-absorption of CdTe QD, which can be made use for future nanosensor development