Cytometric bead array (CBA) is a new analytical technique, which can achieve real-time and rapid detection of targeted components in a small amount of sample. With many advantages of high throughput screening, high specificity and sensitivity, low cost, easy operation and good repeatability, this CBA technique has been widely used for the detection of various components in foods, agricultural products and environmental samples. Recently, it has got significant development in rapid detection of small molecules. This review briefly introduced the theory of CBA technique, summarized the application in the analysis of small molecules, such as mycotoxins, pesticide residues, shellfish toxins, and then prospected the application of trace small molecules detection in the complex matrices of traditional Chinese medicine and the development trend of it.
Drug Contamination ; High-Throughput Screening Assays ; instrumentation ; methods ; Immunoassay ; instrumentation ; methods ; Microspheres ; Pesticides ; analysis ; Toxins, Biological ; analysis

Mink plasmacytosis, caused by Aleutian Mink Disease Virus (AMDV), poses a threat to the development of the animal fur industry. Neutralizing antibodies against AMDV may result in a persistent infection rather than providing protection for minks. To date,no specific methods to prevent or cure this disease have been developed. In order to eliminate mink plasmacytosis, antibody detection technology has been used globally as a dominant approach to screen for AMDV-positive minks. This paper introduces the classical technology, counterimmunoelectrophoresis and emerging technology in terms of AMDV antibody detection,and provides a glimpse into the future development of these technologies.
Aleutian Mink Disease ; diagnosis ; immunology ; virology ; Aleutian Mink Disease Virus ; immunology ; isolation & purification ; Animals ; Antibodies, Viral ; immunology ; Immunoassay ; instrumentation ; methods ; Mink

This article summarizes biological detection techniques based on magnetic signal of magnetic nanoparticles and the research progress of these techniques in biomedicine. Biological detection based on magnetic nanoparticles is faster, more accurate and more convenient compared to traditional optical techniques and causes much attention. It can be classified into giant magneto resistive biosensor (GMR), magnetic relaxation switch (based on T2 relaxation time), AC susceptibility (based on Brownian relaxation) and magnetic lateral flow immunoassay. These techniques can be combined with nanotechnology, microfluidics, immunoassay and bio-chips and have wide application prospects in clinical diagnosis, biological detection, environmental monitoring and food security areas.
Biosensing Techniques ; instrumentation ; methods ; Immunoassay ; instrumentation ; methods ; Magnetic Phenomena ; Nanoparticles ; chemistry ; Nanotechnology ; instrumentation ; Point-of-Care Systems

A sensitive antibody-based lateral flow dipstick was developed for ginsenoside Re (GRe) detection. The stick consisted of a sample pad, a conjugate pad, membrane and an absorbent pad. The membrane was coated with two capture reagents, GRe-BSA conjugate and goat anti-mouse antibodies, forming a test line and a control line, respectively. The conjugate pad was saturated with colloidal gold particles coated with affinity purified monoclonal anti-GRe antibody. The visual detection limit was 200 microg x L(-1) of GRe and the reaction time was 10 min. The Panax ginseng roots were identified after these samples (10 mg) were extracted with 5 mL tap water for 30 min at room temperature, and the extracts were tested by the dipsticks and ELISA kit. The true and false P. ginseng could be distinguished with dipsticks. The dipstick could be used to detect the quality of the P. ginseng samples when the extract was diluted 100-folds. The results were compared with those obtained using an indirect competitive enzyme-linked immunosorbent assay (icELISA). The dipstick assay proved to be a sensitive and rapid tool for quality control of P. ginseng.
Animals ; Antibodies, Monoclonal ; immunology ; Counterfeit Drugs ; analysis ; Ginsenosides ; analysis ; Immunoassay ; instrumentation ; methods ; Mice ; Panax ; chemistry ; Reagent Strips ; Time Factors

PURPOSE: Tumor marker concentrations in a given specimen measured by different analyzers vary according to assay methods, epitopes for antibodies used, and reagent specificities. Although great effort in quality assessment has been instituted, discrepancies among results from different analyzers are still present. We evaluated the assay performance of the UniCel(TM) DxI 800 automated analyzer in measuring the alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 125, CA 15-3 and CA 19-9 tumor markers. MATERIALS AND METHODS: The linearity and precision performance of the five tumor marker assays were evaluated, and concentrations of the respective markers as measured by DxI were compared to those measured by other conventional analyzers (ADVIA Centaur(TM) and Vitros(TM) ECi) using 200 specimens collected from 100 healthy persons and 100 patients with respective cancers. RESULTS: The linear fits for all five tumor markers were statistically acceptable (F=4648 for AFP, F=15846 for CEA, F=6445 for CA 125, F=2285 for CA 15-3, F=7459 for CA 19-9; p<0.0001 for all). The imprecision of each tumor marker assay was less than 5% coefficient of variation, except for low and high concentrations of AFP. The results from UniCel(TM) DxI 800 were highly correlated with those from other analyzers. CONCLUSION: Our results demonstrate that UniCel(TM) DxI 800 has good linearity and precision performance for the tumor markers assayed in this study. However, there were discrepancies between assaying methods. Efforts to standardize tumor marker assays should be undertaken, and the redetermination of cut-off levels is necessary when developing methods of analyzing tumor markers.
CA-125 Antigen/blood ; CA-19-9 Antigen/blood ; Carcinoembryonic Antigen/blood ; Humans ; Immunoassay/*instrumentation/*methods ; Tumor Markers, Biological/*blood ; alpha-Fetoproteins/metabolism

BACKGROUND: Maternal serum prenatal quadruple screening includes testing for alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), unconjugated estriol (uE3), and dimeric inhibin A (DIA). We evaluated quadruple screening using an automated platform and looked for any ethnic differences in the median values of each marker. METHODS: We measured the concentrations of each quadruple test analyte using the UniCel DxI 800 system (Beckman Coulter, USA) in 788 Korean mid-trimester maternal serum samples and calculated their median values using Benetech software (Benetech, Canada). We also compared the results with those obtained using the Immulite 2000 assay (Siemens Healthcare Diagnostics, USA) or ELISA (DSL, USA) in 442 samples. RESULTS: We obtained mid-trimester median values for each marker. The following are the comparative results for each test using the Immulite 2000 assay or ELISA (x) and the UniCel DxI 800 immunoassay (y): AFP, y=1.10x+0.01, r=0.925; uE3, y=0.28x+0.24, r=0.885; hCG, y=1.22x-3047.8, r=0.944; and DIA, y=0.86x+15.31, r=0.833. Assay results for each of the four markers showed good correlations. However, significant biases necessitated new median calculations of prenatal risk estimates in all four tests. CONCLUSIONS: We established gestational age-specific second-trimester median values for four markers in Korean samples using the UniCel DxI 800 immunoassay system. Despite significant bias, there were good correlations between the results obtained using the UniCel DxI 800 immunoassay and those obtained using the Immulite 2000 assay.
Biological Markers/blood ; Chorionic Gonadotropin/blood ; Enzyme-Linked Immunosorbent Assay ; Estriol/blood ; Female ; Gestational Age ; Humans ; Immunoassay/instrumentation/*methods ; Inhibins/blood ; Pregnancy ; Pregnancy Trimester, Second ; *Prenatal Diagnosis ; Reference Values ; Republic of Korea ; alpha-Fetoproteins/analysis

To research piezoelectric immunosensor array for rapid detecting HIV(1+2), piezoelectric immunosensor array matrix was designed. HIV(1+2)C1 antigen was immobilized onto the silver electrodes of quartz-crystal microbalance, which was modified with adsorption and cross-linked method. In the clean air flow and monitoring environment, standard quality control and clinical serum sample were detected. The linear range for the measurement of HIV(1+2) was 0.01-0.2 NCU/ml. The sensitivity, specificity and accuracy of HIV(1+2) piezoelectric protein sensor array were 91.7%, 93.3% and 92.7% respectively.
Biosensing Techniques ; instrumentation ; methods ; Electrodes ; HIV ; isolation & purification ; HIV Antibodies ; blood ; Humans ; Immunoassay ; methods ; Protein Array Analysis ; instrumentation ; methods ; Quartz ; Reproducibility of Results ; Sensitivity and Specificity

Based on integrate circuit (IC) technology, an eight-channel gold electrodes (GEs) array was developed. The immunosensor array is prepared by co-immobilizing thionine and Hepatitis B (HB) antibody on the gold electrodes through covalently binding them to GEs with a cysteamine/glutaraldehyde linkage. Hepatitis B surface antigen (HBsAg) was detected qualitatively and quantitatively by the peak current decrease percentage of the thionine. HBsAg positive/negative standard serum was well defined by the array. 8-channel synchronous detection for HBsAg was noted to be of good accuracy and reliability. The results of its clinical application were in good agreement with the results from ELISA.
Biosensing Techniques ; instrumentation ; Electric Impedance ; Electrochemistry ; instrumentation ; methods ; Electrodes ; Hepatitis B Antibodies ; immunology ; Hepatitis B Surface Antigens ; analysis ; immunology ; Humans ; Immunoassay ; instrumentation ; methods

We designed a novel microcantilever immuosensor based on magnetic microbead, applying different-sized CdSe QDs as fluorescent probes and polystyrene magnetic microbead. The novel microcantilever immuosensor used fluorescent probes embedded polystyrene microbeads and specific antibodies on the surface of the polystyrene microbead. In addition, we studied the mechanism of the on-chip magnetic separation, the structure of micro-electromagnet and the microbead magnetization by the micro-magnetic field, the snake-shaped planar micro-electromagnet for the novel microcantilever immuosensor.
Antibodies ; analysis ; Biosensing Techniques ; instrumentation ; methods ; Cadmium Compounds ; chemistry ; Equipment Design ; Immunoassay ; instrumentation ; methods ; Magnetics ; Micro-Electrical-Mechanical Systems ; instrumentation ; Microspheres ; Nanotechnology ; Polystyrenes ; chemistry ; Quantum Dots ; Selenium Compounds ; chemistry

By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157:H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor's resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0x10(2) colony forming units (CFU)/ml E. coli O157:H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed.
Antibodies ; chemistry ; Biosensing Techniques ; instrumentation ; methods ; Colony Count, Microbial ; Crystallization ; Electrochemistry ; Electrolytes ; Equipment Design ; Escherichia coli O157 ; metabolism ; Gold ; chemistry ; Immunoassay ; instrumentation ; methods ; Oxidation-Reduction ; Quartz ; Signal Processing, Computer-Assisted ; Software ; Time Factors