Simultaneous determination of aflatoxin B_1,B_2,G_1,G_2,M_1,M_2 in Eupolyphaga Steleophaga by immunoaffinity column clean-up and HPLC-FLD with post-column photochemical derivatization / 中国中药杂志

The contamination of aflatoxin B_1,B_2,G_1,G_2,M_1 and M_2 in Eupolyphaga Steleophaga was determined by immunoaffinity column clean-up and HPLC-FLD with post-column photochemical derivatization. Chromatographic separations were carried out using a Cloversil C_(18) column( 4. 6 mm×250 mm,5 μm) that were eluted in isocratic with methanol-acetonitrile-water( 20 ∶ 20 ∶ 60) as the mobile phase. The excitation wavelength and the emission wavelength of fluorescence detector were maintained at 360 nm and 450 nm,respectively. The flow rate was 0. 8 m L·min~(-1),and the column temperature was 30 ℃ ． The sample was prepared using the immunoaffinity column,then the recovery was measured with 75. 47%-101. 8% with RSD values lower than 6. 7%. A total of 20 batches of Eupolyphaga Steleophaga samples were assayed. According to the Chinese Pharmacopoeia( 2015 edition,part 1),the aflatoxin B_1 limit should be less than 5 μg·kg~(-1),and the sum of aflatoxins( AFB_1,AFB2,AFG_1,AFG_2) should be less than 10 μg·kg-1. Therefore,the positive rate of the 20 samples was 50. 0%,and 7 batches of samples exceeded the standard,and the over-standard rate was as high as 70. 0%. Among them,aflatoxins B_1,B_2,G_1,G_2,M_1,and M_2 were detected in three batches( SD-1,AH-1,AH-3),and aflatoxins B_1,B2,G1,G2,and M1 were detected in one batch( AH-7). The results showed that the newly developed method in this work is suitable for the simultaneous determination of six aflatoxins in Eupolyphaga Steleophaga,and also suggested that it should be of high values to take the contamination with aflatoxins into concerns.

Study on the content of aflatoxin Bt in 35 traditional Chinese medicine decoction pieces / 国际中医中药杂志

Objective To investigate the contamination of aflatoxin B1 in traditional Chinese medicine decoction pieces.and to provide evidence for the development of sdandards and scientific management.Methods Immunoaffinity column and post-column photochemical derivatization were used to detect and quantify aflatoxin B1 in 35 traditional Chinese medicines.Results A total of 48.57％(17 out of 35 batches) traditional Chinese medicine were contained aflatoxin B1.The contents of aflatoxin B1 in all contaminated varieties were less than 1μg/kg,except for Sterculia lychnophorae Semen,Foeniculi Fructus,Corydalis Rhizoma,which exceeded the standard.Conclusions The tested traditional Chinese medicine are highly contaminated of aflatoxin,it is necessary to further study the increase of aflatoxin content under the examination of Chinese Pharmacopoeia Foeniculi Fructus and Corydalis Rhizoma to better control its quality.The degree of aflatoxin B1 pollution is reated to the site of drug use and the place of origin.

Detection of Four Aflatoxins in Gelatin Drugs by Immunoaffinity Column Clean-up and HPLC-MS/MS / 中国药学杂志

OBJECTIVE: To develop an immunoaffinity column clean-up and high performance liquid chromatography coupled with triple quadrupole mass spectrometry(HPLC-MS/MS) method to determine aflatoxins in gelatin drugs. METHODS: The analysis was performed by an HPLC-MS/MS system with X-Brigde-C18(3.0 mm×50 mm, 3.5 μm)column. Multiple-reaction monitoring (MRM) was performed to identify and quantify aflatoxin B1, B2, G1 and G2, which were extracted from Asini Coril Colla, Cervil Cornus Colla, and Testudinis Carapacis Colla with 60% methanol solution. RESULTS: Linear calibration curves were obtained with r≥0.997 9. The precision of the method was showed by RSDs (n=6) ranging from 1.2% to 4.1%. The recoveries were determined at three concentration levels and ranged from 77.3% to 94.6%. The ranges of LOQs were from 0.5 to 0.8 μg·L-1 and the RSDs (n=9) of intra-day precision and inter-day precision were from 1.1% to 2.9% and from 1.5% to 2.8%, respectively. CONCLUSION: The method is specific, simple and rapid to detect aflatoxins in gelatin drugs.

Determination of aflatoxins in animal medicines by immunoaffinity column and HPLC-FLD with photochemical derivatization fluorescence detection / 中草药

Objective: To determine the aflatoxins residue of animal medicines by immunoaffinity column HPLC method with post column photochemical derivatization and fluorescence detection, and to evaluate the feasibility of this method. The contamination status of aflatoxins in animal medicines was evaluated according to the determination data of aflatoxin contamination in animal medicines. Methods: After extraction by organic solvent and purification by immunoaffinity column, aflatoxins samples were analyzed by HPLC with fluorescence detection after photochemistry derivation. The recovery rates of aflatoxins in animal medicines, especially the species easily contaminated by aflatoxin, were then determined by adding aflatoxin standard mixtures. Finally, aflatoxins in animal medicines were determined and the results were analyzed. Results: Recovery rates of aflatoxin B1, B2, G1, and G2 were from 70% to 120%. Twenty-four batches of six kinds in 64 batches of 16 kinds of animal medicines were contaminated by aflatoxins, and the contamination rate was 37.5%. Thirteen batches of four kinds of animal medicines exceeded the limit of Chinese Pharmacopoeia of (2015 Edition), and the rate was 20.3%. Conclusion: This method can be used to determine aflatoxins in animal medicines. Some species of animal medicines are likely to be contaminated by aflatoxins, so the aflatoxin control in those animal medicines should be put forward to ensure the safety of drug use.

Determination of Aflatoxin B1 in Edible Vegetable Oil by HPLC with Post-column Derivation / 中国药师

Objective:To establish an HPLC method with post-column derivation for the determination of aflatoxin B1 in edible vegetable oil. Methods:An advanced biotechnology-immunoaffinity column was used for the extraction of aflatoxin Bl from the samples, and an HPLC method with post-column derivation was applied to detect aflatoxin Bl in edible vegetable oil, and the results were com-pared with those of the national standard thin layer fluorescence method. Results:The linear range of aflatoxin Bl was 10. 2-51. 0 ng · ml-1(r=0. 9996), the average recovery was 87. 3%(RSD=0. 96%, n=6), and the detection limit was 1 μg · kg-1. Conclu-sion:The method is simple, rapid and sensitive, which can be used as a promoted conventional method for the detection of a large number of samples.

Methodology on specific knock out of glycyrrhizic acid by immunoaffinity chromatography column / 中草药

Objective: To prepare the glycyrrhizic acid (GA) immunoaffinity chromatography column, which could specifically knock out the GA. Methods: An immunoaffinity chromatography (IAC) column was developed by covalently coupling the anti-GA-MAb to CNBr-activated Sepharose™ 4B. The concentration of GA was detected by HPLC, and the maximum coupling capacity, stability, precision, and accuracy of the IAC column for GA were studied. Results: The maximum capacity of the IAC column for GA was 1.326 11 mg, the precision (RSD) of GA was 0.65%, and the accuracy (RE) was 0.37%. RSD of GA stayed 1.37% during 32 d, which showed a pretty well stability. Conclusion: GA-IAC column could rapidly, effectively, and stably knock out the GA.

Preparation and Application of Immunoaffinity Column for Multi-mycotoxins / 分析化学

The three-in-one immunoaffinity column ( IAC ) for the determination of aflatoxin B1 ( AFB1 )-zearalenone (ZEN)-deoxynivalenol (DON) was prepared with rProtein A-sepharose 4B as the column matrix. The comprehensive performance ( such as nonspecific adsorption, column blank, column capacity, column efficiency and sample standard addition recovery rate) was evaluated and investigated. The results showed that, the column capacities of AFB1 , ZEN, DON were 295 ng per 0. 25 mL gel, 905 ng per 0. 25 mL gel, 2342 ng per 0. 25 mL gel, respectively, and the column blank was 0. The average recoveries of AFB1 , ZEN and DON were 97. 4%, 98. 0% and 98. 4%, respectively. By optimizing conditions, the samples were extracted using the mixture of methanol and water (80:20, V/V), and diluted with phosphate buffered saline (contain 0. 1% Tween-20, PBST). The detection results of FAPAS (Food Analysis Performance Assessment Scheme) by different batch three-in-one columns were close to the target value. The prepared three-in-one immunoaffinity column which could take the place of conventional single immunoaffinity column was able to meet the requirement for treatment of food and feed samples, and lay a foundation for one step enrichment, purification and detection of multi-mycotoxins.

Determination of Aflatoxins and Zeranols in Animal-Originated Foods by High Performance Liquid Chromatography-Tandem Mass Spectrometry Combined With Immunoaffinity Clean-up Column / 分析化学

A high performance liquid chromatography-tandem mass spectrometric ( HPLC-MS / MS) method coupled with an immunoaffinity clean-up column was successfully developed for determination of aflatoxins (AFB1 , AFB2 , AFG1 , AFG2 , AFM1 and AFM2 ) and zeranols ( α-zeranol, β-zeranol, α-zearalenol,β-zearalenol, zearalanone and zearalenone ). The sample was extracted with methanol-acetonitrile (20∶ 80, V/ V) after enzymatic digestion by β-glucuronidase / sulfatase, and the extraction solution was passed through glassy fiber filter paper and then diluted with phosphate buffer solution (PBS). The reconstituted solution was cleaned up with IAC-AZ immunoaffinity column, and then analyzed by HPLC-MS / MS in multiple reaction monitoring (MRM) mode. The results indicated that the linear detection range was 0. 03-6. 0 μg / L for AFB2 and AFG2 , and 0. 05-20 μg / L for the rest compounds. The correlation coefficients were above 0. 999. The limits of detection (LOD) and limits of quantitation (LOQ) were 0. 01-0. 03 μg / kg and 0. 04-0. 09 μg / kg, respectively. The recoveries of the aflatoxins and zeranols were in the range of 73. 6% -98. 4% at the spiked levels of 0. 5, 1 and 5 μg / kg, and the relative standard deviations (RSDs) were in the range of 1. 9% -11. 2% . The method was proved to be simple and accurate, and suitable for the rapid determination of aflatoxins and zeranols in animal-originated foods.

Occurrence of aflatoxin M1 in bovine milk samples consumed in different regions of Brazil / Ocorrência de aflatoxina M1 em amostras de leite bovino consumido em diferentes regiões do Brasil

Two hundred and fifty-seven samples of milk proceeding from different geographical regions of Brazil were analyzed for determining the presence of aflatoxin M1 (AFM1). The AFM1 extraction was carried out using immunoaffinity column, separated by reversed-phase (C-18) high performance liquid chromatography (HPLC), and quantified by fluorescence detector. The Limits of Quantification (LOQ) were 0.008 µg/kg and 0.080 µg/kg to the fluid and the powder milk, respectively. AFM1 were detected in 209 (81.3 %) samples, being 26 (63.4 %), 105 (84.0 %) and 78 (85.7 %) of pasteurized, UHT (Ultra-high Temperature) and powder milk, respectively. The highest concentration of AFM1 in powder milk was found in one sample from Minas Gerais (1.210 µg/kg). In UHT and pasteurized milk, the highest levels were detected in one sample from Sergipe (0.120 µg/kg) and one sample from Goiás (0.050 µg/kg), respectively. None of the samples analyzed in this study exceeded the Brazilian legal limits for AFM1.

Duzentas e cinquenta e sete amostras de leite provenientes das diferentes regiões geográficas do Brasil foram analisadas para realizar a determinação de aflatoxina M1 (AFM1). As AFM1 foram extraídas por meio de colunas de imunoafinidade, separadas por cromatografia líquida de alta eficiência em fase reversa (C-18) e quantificadas por detector de fluorescência (CLAE-FL). Os limites de quantificação (LQ) foram de 0,008 µg/kg e 0,080 µg/kg para o leite fluido e em pó, respectivamente. AFM1 foi detectada em 209 (81,3 %) amostras, sendo 26 (63,4 %), 105 (84,0 %) e 78 (85,7 %) para o leite pasteurizado, UHT (Ultra-high Temperature) e em pó, respectivamente. A maior concentração de AFM1 no leite em pó foi encontrada em uma amostra proveniente de Minas Gerais (1,210 µg/kg). No leite UHT e pasteurizado, os maiores níveis foram encontrados em uma amostra de Sergipe (0,120 µg/kg) e Goiás (0,050 µg/kg), respectivamente. Nenhuma amostra analisada ultrapassou os limites da legislação brasileira em vigor para AFM1.

Occurrence of aflatoxin M1 in bovine milk samples consumed in different regions of Brazil / Ocorrência de aflatoxina M1 em amostras de leite bovinoconsumido em diferentes regiões do Brasil

Two hundred and fifty-seven samples of milk proceeding from different geographical regionsof Brazil were analyzed for determining the presence of aflatoxin M1 (AFM1). The AFM1extraction was carried out using immunoaffinity column, separated by reversed-phase (C-18) high performance liquid chromatography (HPLC), and quantified by fluorescence detector.The Limits of Quantification (LOQ) were 0.008 µg/kg and 0.080 µg/kg to the fluid and the powder milk, respectively. AFM1 were detected in 209 (81.3 %) samples, being 26 (63.4 %), 105(84.0 %) and 78 (85.7 %) of pasteurized, UHT (Ultra-high Temperature) and powder milk,respectively. The highest concentration of AFM1 in powder milk was found in one sample from Minas Gerais (1.210 µg/kg). In UHT and pasteurized milk, the highest levels were detected inone sample from Sergipe (0.120 µg/kg) and one sample from Goiás (0.050 µg/kg), respectively.None of the samples analyzed in this study exceeded the Brazilian legal limits for AFM1.

Duzentas e cinquenta e sete amostras de leite provenientes das diferentes regiões geográficasdo Brasil foram analisadas para realizar a determinação de aflatoxina M1 (AFM1). As AFM1foram extraídas por meio de colunas de imunoafinidade, separadas por cromatografia líquidade alta eficiência em fase reversa (C-18) e quantificadas por detector de fluorescência (CLAE-FL).Os limites de quantificação (LQ) foram de 0,008 µg/kg e 0,080 µg/kg para o leite fluidoe em pó, respectivamente. AFM1 foi detectada em 209 (81,3 %) amostras, sendo 26 (63,4 %), 105(84,0 %) e 78 (85,7 %) para o leite pasteurizado, UHT (Ultra-high Temperature) e em pó,respectivamente. A maior concentração de AFM1 no leite em pó foi encontrada em umaamostra proveniente de Minas Gerais (1,210 µg/kg). No leite UHT e pasteurizado, os maioresníveis foram encontrados em uma amostra de Sergipe (0,120 µg/kg) e Goiás (0,050 µg/kg),respectivamente. Nenhuma amostra analisada ultrapassou os limites da legislação brasileira emvigor para AFM1.

Expression and purification of CDNF and preparation of its polyclonal antibodies / 中国免疫学杂志

Objective: To obtain purified and functional CDNF-his recombinant protein and prepare its polyclonal antibodies.Methods:Preparation of recombinant CDNF-his was carried out in HEK 293 T cells with pVR1012-CDNF-his successfully constructed transfected into them.Then,the recombinant protein was purified by Ni-NTA immunoaffinity chromatography.The purity was analyzed by SDS-PAGE and the protein′s identity was tested by Western blot.MTT was used to verify the biological function of the protein purified.New Zealand white rabbits were immunized with purified CDNF-his protein for preparation of polyclonal antibodies.Results:pVR1012-CDNF-his expressed successfully in HEK 293 T cells.The purity of protein was up to more than 90%after purification.MTT showed that CDNF-his was able to protect PC 12 cells from damage by 6-OHDA.The polyclonal antibody was detected at the end of animal immunizing process.Conclusion: A method to express and purify protein using HEK 293T cell and following Ni-NTA immunoaffinity chromatography has been built.CDNF-his with biological activity is obtained based that.Finally, polyclonal antibodies of CDNF were generated successfully.

Determination of Tetrodotoxin in Marine Organisms by High Performance Liquid Chromatography-Mass Spectrometry and Cleaned up by Immunoaffinity Column / 分析化学

A method was developed for the determination of tetrodotoxin in marine organisms by high perfor-mance liquid chromatography-mass spectrometry with immunoaffinity column. The samples were extracted with 1% acetic acid methanol solution and diluted with phosphate buffer at pH 7-8. After cleaned up by immuno-affinity column, the samples were analyzed by LC-MS/MS and quantitatively determined by external standard method. The chromatographic separation was performed on an ACQUITY UPLC BEH Amide column with gradient elution by using acetonitrile and 5 mol/L ammonium acetate solution containing 0. 1% formic acid as mobile phase. Detection was carried out by electrospray positive ionization mass spectrometry in the multiple reaction monitoring mode. Linear ranges of TTX was in the range of 0. 3 -20. 0 μg/L with correlation coeffi-cient more than 0. 997. The quantification limit of the method was 0. 3 μg/kg. The recoveries of standard addition for tetrodotoxin were 88. 7%-102. 3%, and the relative standard deviation was 2. 0%-6. 4%. The method could be used to identify and quantify tetrodotoxin in marine organisms with satisfactory reproducibility and sensitivity.

Niveles de Ocratoxina A y Aflatoxinas totales en cafés de exportación de Panamá por un método de ELISA

Se realizó un estudio de las condiciones del procesamiento del café de exportación en 15 beneficios, ubicados en Chiriquí, región occidental de Panamá. Además se analizaron 21 muestras de café procesado (grano verde), provenientes de los beneficios. Las muestras fueron analizadas microbiológicamente y se cuantificaron las Aflatoxinas totales (B1, B2, G1 y G2) y Ocratoxina A (OTA), mediante el método de inmunoafinidad ELISA. Se determinó un límite de detección de 0,017 ng/mL, para la Ocratoxina A, lo que equivale a una concentración de 0,829 μg/kg en la muestra, y un límite de detección de 0,027 ng/mL, para las Aflatoxinas totales, lo que equivale a una concentración de 1,350 μg/kg de Aflatoxinas totales. En la muestra, se encontró que cuatro de las 21 (19%) resultaron positivas a la presencia de Ocratoxina A y tres, a la presencia de Aflatoxinas totales (14%). Las muestras presentaron niveles de Ocratoxina A en el rango de 4,90-37,73 μg/kg; sólo tres de ellas superaron el límite máximo permitido por la Unión Europea, para la concentración de Ocratoxina, que es de 5,0 μg/kg. Las Aflatoxinas totales se encontraron en el rango de 1,51- 1,93 μg/kg, por debajo de los 10 μg/kg, que es el límite máximo permitido en el café por la Unión Europea. Los resultados nos indican que el procesamiento de café producido en Panamá cumple satisfactoriamente con los estándares internacionales de manejo poscosecha, lo que conduce a una baja incidencia de hongos productores de micotoxinas y niveles muy bajos de micotoxinas.

Levels of Ochratoxin A and total Aflatoxins in Panamanian exportation coffee by an ELISA Method. A study about processing conditions of exportation coffee in 15 benefits located in Chiriquí, western region of Panama, was conducted. In addition, 21 samples of processed coffee (green beans), from the benefits, were analyzed. The samples were microbiologically tested in order to quantify total aflatoxins (B1, B2, G1 and G2) and Ochratoxin A (OTA), using the immunoaffinity ELISA method. A detection limit of 0.017 ng/mL, was determined for Ochratoxin A, which is equivalent to a concentration of 0.829 μg/kg, and a detection limit of 0.027 ng/mL, for total aflatoxins, which is equivalent to a concentration of 1.350 μg/kg. It was found that four (19%) out of the 21 samples were positive to the presence of Ochratoxin A and three (14%) to the presence of total aflatoxins. Samples showed levels of Ochratoxin A in the range 4.90 - 37.73 μg/kg; only three of them exceeded the maximum limit allowed by the European Union, for the concentration of Ochratoxin, which is of 5.0 μg/kg. Total aflatoxins were found in the range 1.51 - 1.93 μg/kg, below 10μg/kg which is the maximum limit allowed for coffee by the European Union. The results indicate that the processing of coffee produced in Panama successfully meets international standards for postharvest handling, which leads to a low incidence of mycotoxins and very low levels of mycotoxin- producing fungi.

Determination of Tetrodotoxin in Human Urine and Plasma after Immunoaffinity Column Clean-up Using Ultra-Performanc Hydrophilic Interaction Chromatography Coupled with Triple Quadrupole Mass Spectrometry / 分析化学

Anultra-performancehydrophilicinteractionliquidchromatography-triplequadrupolemass spectrometric ( UPLC-MS/MS) method was developed for the determination of tetrodotoxin ( TTX) in human urine and plasma. After the sample was cleaned-up and concentrated by immunoaffinity column, the separation of the TTX was carried out on an Acquity UPLC BEH amide column (100 mm×2. 1 mm, 1. 7 μm) with gradient elution using mobile phases of 0. 1% ( V/V) formic acid in water and acetonitrile. The analyte was detected by positive electrospray ionization mass spectrometry in the multiple reaction monitoring ( MRM) mode, and quantified by external solvent standard calibration. The measuring ranges of TTX in urine and plasma were 0. 05-400 μg/L. The average recoveries were 92%-95% and 91%-96% for TTX respectively spiked in urine and plasma with relative standard deviations of 3 . 3%-7 . 2% and 3 . 9%-7 . 8% ( n=5 ) . The limits of detection (LOD, S/N=3) and limits of quantitation (LOQ, S/N=10) of TTX were 0. 02 μg/L and 0. 05μg/L for urine and plasma, respectively. This method is suitable for the detection of TTX in urine and plasma for both forensic and clinical purposes.

Human Infections with Liver and Minute Intestinal Flukes in Guangxi, China: Analysis by DNA Sequencing, Ultrasonography, and Immunoaffinity Chromatography

The prevalence of liver and intestinal fluke infections was determined by surveying inhabitants of Hengxuan, Fusui, and Shanglin villages which were known to be endemic for liver flukes in Guangxi, China in May 2010. A total of 718 people were examined for helminth eggs by the Kato-Katz thick smear technique, ultrasonography, immunoaffinity chromatography, and DNA sequencing. The overall egg positive rate was found to be 59.6% (28.0-70.6%) that included mixed infections with liver and intestinal flukes. Cases showing higher than 20,000 eggs per gram of feces (EPG) were detected between 1.3% and 16.2%. Ultrasonographic findings exhibited overall 28.2% (72 of 255 cases) dilatation rate of the intrahepatic bile duct. Clonorchis sinensis infection was detected serologically in 88.3% (38 of 43 cases) among C. sinensis egg positive subjects by the immunoaffinity chromatography using a specific antigen for C. sinensis. For differential diagnosis of the liver and intestinal flukes, more precise PCR and nucleotide sequencing for copro-DNA were performed for 46 egg positive cases. Mixed infections with C. sinensis and Metagonimus yokogawai were detected in 8 of 46 egg positive cases, whereas 29 specimens were positive for Haplorchis taichui. Ultrasonographic findings and immunoaffinity chromatography results showed usefulness, even in a limited way, in figuring out of the liver fluke endemicity.

A novel mycotoxin purification system using magnetic nanoparticles for the recovery of aflatoxin B1 and zearalenone from feed

In this study, we developed a novel tool for purifying two mycotoxins, aflatoxin B1 (AFB1) and zearalenone (ZEN), in feed. This system utilized monoclonal antibodies (mAbs) against AFB1 and ZEN, and magnetic nanoparticles (MNPs). Among ten MNPs with different diameters and functional groups, a 100-nm diameter MNP (fMA) conjugated to an amine group (-NH2) was found to be optimum for coupling with mAbs. The optimal mAb concentrations for coupling to the fMA along with mycotoxin purification capacities of the fMA-mAb conjugates (fMA-AFB1 and fMA-ZEN) were determined. A comparison of mean recovery rates (from corn and product X feed) between the fMA-mAb conjugates and immunoaffinity columns (IAC-AFB1 and IAC-ZEN) showed that the rate for fMA-AFB1 (90~92% and 81~88%) was higher (p > 0.05) than that of IAC-AFB1 (81~84% and 72~78%) for AFB1 (5, 10, 15 ng/mL), and the rate for fMA-ZEN (99~100% and 92~94%) was significantly higher (p 30 min). This study suggests that the novel purification system we developed would be a useful tool for monitoring and regulating mycotoxin contamination in feed, and replace IAC methods.

Development and characterization of a potential diagnostic monoclonal antibody against capsid protein VP1 of the chicken anemia virus

Chicken anemia virus (CAV) is an important viral pathogen that causes anemia and severe immunodeficiency syndrome in chickens worldwide. In this study, a potential diagnostic monoclonal antibody against the CAV VP1 protein was developed which can precisely recognize the CAV antigen for diagnostic and virus recovery purposes. The VP1 gene of CAV encoding the N-terminus-deleted VP1 protein, VP1Nd129, was cloned into an Escherichia (E.) coli expression vector. After isopropyl-beta-D-thiogalactopyronoside induction, VP1Nd129 protein was shown to be successfully expressed in the E. coli. By performing an enzyme-linked immunoabsorbent assay using two coating antigens, purified VP1Nd129 and CAV-infected liver tissue lysate, E3 monoclonal antibody (mAb) was found to have higher reactivity against VP1 protein than the other positive clones according to the result of limiting dilution method from 64 clones. Using immunohistochemistry, the presence of the VP1-specific mAb, E3, was confirmed using CAV-infected liver and thymus tissues as positive-infected samples. Additionally, CAV particle purification was also performed using an immunoaffinity column containing E3 mAb. The monoclonal E3 mAb developed in this study will not only be very useful for detecting CAV infection and performing histopathology studies of infected chickens, but may also be used to purify CAV particles in the future.

HPLC determination of aflatoxin G_2、G_1、B_2、B_1 in 6 traditional Chinese drugs / 中成药

AIM:To bring forward a method of determining aflatoxin G_2、G_1、B_2、B_1 in six kinds of traditional Chinese drugs by HPLC.METHODS:After being extracted by 70% methanol,purified by immunoaffinity column,aflatoxins were analysed by HPLC with fluorescence detection.RESULTS:Aflatoxin G_2、B_2 showed a good linear relationship at a range of 1.5-60pg,and Aflatoxin G_1、B_1 at a range of 5-200 pg,r＞0.999 9.The recovery was between 60%-120%.CONCLUSION:The method is simple,accurate and can be used to determine aflatoxin G_2、G_1、B_2、B_1 in Naoliqing Pill,Renshen Yangrong Pill,Rensen Jiapi Pill,Sanqi Tablet,Jinshuibao Capsule and Bailine Capsule.

Micropreparation of a Native PHGPx Protein From Radish Seedlings by Immunoaffinity Chromatography / 生物化学与生物物理进展

Radish phospholipid hydroperoxide glutathione peroxidase (RsPHGPx) was identified as a mitochondrion-targeting PHGPx in previous work. To determine its cleavage site of the targeting peptide, the immunoaffinity chromatography (IAC) purification approach was carried out to isolate the native RsPHGPx protein.Polyclonal antibodies directed against recombinant RsPHGPx were raised in rabbit. Monospecific anti-RsPHGPx antibodies were isolated by means of affinity chromatography using the recombinant RsPHGPx as affinity ligand, and employed in assembling an IAC column. A single-step, highly specific and easy-to-use protocol was developed for purification of the active RsPHGPx protein through the assembled IAC column. Using this approach, a specific protein of the expected molecular size was obtained from the mitochondrial fraction of radish seedlings. Western blot analysis showed that it could be specifically recognized by anti-RsPHGPx antibodies, and an enzyme activity assay indicated that it exhibited significant PHGPx activity, suggesting that the purified protein should be the desired native RsPHGPx. These results will lead to clarification of the targeting peptide and the active mature protein of RsPHGPx and will be helpful to further probe the intracellular localization mechanism and biological fun ction of this plant PHGPx.

Afloxina M1 em queijo prato e parmesäo determinada por coluna de imunoafinidade e cromatografia líquida / Aflatoxin M1 in soft and parmesan chesse by immunoaffinity column and liquid chromatography

Produtos derivados de leite, como o queijo, podem estar com aflatoxina M1 (AFM1) quando o gado leiteiro consome raçäo contendo aflatoxina B1 (AFB1). Amostras de queijo tipo prato e tipo parmesäo ralado foram coletadas na cidade de Belo Horizonte pela Vigilância Sanitária de Minas Gerais - Brasil. Foi obtido um extrato purificado através de extraçäo com diclorometano, seguido de lavagem com n-hexano e purificaçäo em coluna de imunoafinidade. A quantificaçäo da AFM1 foi feita por cromatografia líquida de alta eficiência (CLAE) usando detetor de fluorescência. AFM1 foi detectada em todas as marcas de queijo tipo prato analisadas, em uma faixa de concentraçäo de 0,02 a 0,54 ng/g e média de 0,15 ng/g. Em queijo ralado, tipo parmesäo, AFM1 foi detectada em 13 das 14 marcas de amostras analisadas (93 por cento), em faixa de concentraçäo de 0,04 a 0,30 ng/g e média de 0,14 ng/g. (AU)

Aflatoxin M1 was determined in Soft and Parmesan cheese by immunoaffinity columnand liquid chromatography. Milk products such as cheese may be contaminated by aflatoxin M1 (AFM1)when dairy cattle have consumed feeds contaminated with aflatoxin B1 (AFB1). Samples of Soft andParmesan cheese were collected in Belo Horizonte city, by the Inspection Service of Minas Gerais ­Brazil. A purified extract was obtained by extraction with dichloromethane followed by a washing withn-hexane and immunoaffinity column clean-up. The quantification of AFM1 was done by highperformance liquid chromatography (HPLC) using a fluorescence detector. AFM1 was detected in allsoft cheese brands analysed, in concentrations ranging between 0.02 and 0.54 ng/g and mean level of0.15 ng/g. In grated cheese, Parmesan variety, AFM1 was detected in 13 of 14 brands analysed (93%),in the range 0.04-0.30 ng/g with mean level of 0.14 ng/g. (AU)