Two novel protein chips for the detection of antibodies against porcine parvovirus

Background : PPV is one of the most important pathogens causing porcine reproductive disorder. It has been shown in clinical cases to be a commonly mixed infection with other important swine diseases which can aggravate the severity of the disease and bring serious economic losses to the pig industry. Serological methods, such as hemagglutination inhibition assays (HAI), serum neutralization (SN), and the modified direct complement-fixation (MDCF) test were utilized earlier, whereas the enzyme-linked immunosorbent assay (ELISA) is the most frequently applied assay to detect PPV-specific antibodies Results: We establish the visible protein chip and the cyanine dye 3 (Cy3)-labeled protein chip to detect the clinical serum from pigs. In this study, the recombinant protein VP2 of PPV was expressed in E.coli , purified with nickel magnetic beads, and then printed onto epoxy-coated glass slides for preparation of the protein chip. After a series of experiments, the conditions of antigen protein concentration, incubation time of primary antibody or secondary antibody, and optimal serum dilution fold were optimized, resulting in a successful visible protein chip and Cy3-labeled protein chip. The results showed that the positive serum, diluted up to 6000-fold, can be detected by the visible protein chip, and the positive serum, diluted up to 12,800-fold, can be detected by the Cy3-labeled protein chip, suggesting the high sensitivity of these protein chips. Moreover, the positive detection ratio, sensitivity, and specificity of these two kinds of protein chips were higher than those of commercial ELISA antibody detection kits. Conclusion: Overall, these two protein chips can be used to rapidly diagnose clinical samples with high throughput. Key words: Protein chip; Porcine parvovirus (PPV); Antibody detection; Clinical serum

Two novel protein chips for the detection of antibodies against porcine parvovirus

Background: PPV is one of the most important pathogens causing porcine reproductive disorder. It has been shown in clinical cases to be a commonly mixed infection with other important swine diseases which can aggravate the severity of the disease and bring serious economic losses to the pig industry. Serological methods, such as hemagglutination inhibition assays (HAI), serum neutralization (SN), and the modified direct complement-fixation (MDCF) test were utilized earlier, whereas the enzyme-linked immunosorbent assay (ELISA) is the most frequently applied assay to detect PPV-specific antibodies Results: We establish the visible protein chip and the cyanine dye 3 (Cy3)-labeled protein chip to detect the clinical serum from pigs. In this study, the recombinant protein VP2 of PPV was expressed in E.coli, purified with nickel magnetic beads, and then printed onto epoxy-coated glass slides for preparation of the protein chip. After a series of experiments, the conditions of antigen protein concentration, incubation time of primary antibody or secondary antibody, and optimal serum dilution fold were optimized, resulting in a successful visible protein chip and Cy3-labeled protein chip. The results showed that the positive serum, diluted up to 6000-fold, can be detected by the visible protein chip, and the positive serum, diluted up to 12,800-fold, can be detected by the Cy3-labeled protein chip, suggesting the high sensitivity of these protein chips. Moreover, the positive detection ratio, sensitivity, and specificity of these two kinds of protein chips were higher than those of commercial ELISA antibody detection kits.Conclusion: Overall, these two protein chips can be used to rapidly diagnose clinical samples with high throughput. Key words: Protein chip; Porcine parvovirus (PPV); Antibody detection; Clinical serum

Mass Transport with Asymmetric Peristaltic Propulsion Coated with Synovial Fluid

This article aims to model two-dimensional, incompressible asymmetric peristaltic propulsion coated with Synovial fluid (“non-Newtonian model”) with mass transport. Due to the coating of the same base-fluid at the surface of the channel, the boundaries become non-porous and exert no slip on the fluid particles. Two illustrative models for the viscosity, namely, shear-thinning (Model 1) and shear-thickening (Model 2), are considered, which reveal the presence and integrity of coating. The perturbation method has been applied to linearize the complicated differential equations. Model 1 predicted higher viscosity values and more significant non-Newtonian behavior than Model 2. It is also observed that the shear-thinning model behaved in quite the opposite manner for the shear thickening model. The converse behavior of Model 1 and Model 2 occurs due to a curvature of the flow domain. Moreover, Model 1 is not able to capture the correct exponential viscosity dependence on concentration for the whole range of shear rates. On the other hand, the second model shows a strong relationship with accurate power. Solutions are attained for velocity field, concentration profile, and pressure gradient. The novelty of all the essential parameters is analyzed through graphical results. Furthermore, streamlines are also drawn to determine the trapping mechanism. The present analysis is beneficial in the study of intrauterine fluid dynamics; furthermore, it is applicable in vivo diagnostic; drug delivery; food diagnostics; protein chips; and cell chips and packaging, i.e., smart sensors.

Detection and Quantification of Carbohydrate-Deficient Transferrin by MALDI-Compatible Protein Chips Prepared by Ambient Ion Soft Landing

BACKGROUND Transferrin is synthetized in the liver and is the most important iron-transport carrier in the human body. Severe alcohol consumption leads to alterations in glycosylation of transferrin. Mass spectrometry can provide fast detection and quantification of transferrin isoforms because they have different molecular masses. In this study, we used antibody chips in combination with MALDI-TOF MS for the detection and quantification of transferrin isoforms. METHODS Protein chips were prepared by functionalization of indium tin oxide glass using ambient ion soft landing of electrosprayed antitransferrin antibody. Two microliters of patient serum was applied on the antibody-modified spots, and after incubation, washing, and matrix deposition, transferrin isoforms were detected by MALDI-TOF MS. Peak intensities of each transferrin form were used to calculate total carbohydrate-deficient transferrin (CDT). The CDT values obtained by the MALDI chip method were compared with the results obtained by a standard capillary electrophoresis (CE). RESULTS The chip-based MALDI-TOF MS method was used for enrichment and detection of CDT from human serum. A sample cohort from 186 patients was analyzed. Of these samples, 44 were positively identified as belonging to alcoholic patients, whereas 142 were negative by the MALDI chip approach. The correlation of the data obtained by the CE and the chip-based MALDI was r = 0.986, 95% CI. CONCLUSIONS Functionalized MALDI chips modified by antitransferrin antibody prepared by ambient ion soft landing were successfully used for detection and quantification of CDT from human sera.