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United States Department of Agriculture

Agricultural Research Service

Xiaohua He
Foodborne Toxin Detection and Prevention
Research Molecular Biologist

Phone: (510) 559-5823
Fax: (510) 559-6429
USDA, ARS, PWA, WRRC-FTDP
800 BUCHANAN ST
ALBANY, CA, 94710

Projects
Technologies for Detecting and Determining the Bioavailability of Bacterial Toxins
Appropriated (D)
  Accession Number: 421099
Development of Technologies for Detection and Mitigation of Undesirable Organisms Associated with Food
Nonfunded Cooperative Agreement (N)
  Accession Number: 421821

Publications (Clicking on the reprint icon Reprint Icon will take you to the publication reprint.)
Toxin content of commercial castor cultivars Reprint Icon - (Peer Reviewed Journal)
Mckeon, T.A., Auld, D., Brandon, D.L., Leviatov, S., He, X. 2014. Toxin content of commercial castor cultivars. Journal of the American Oil Chemists' Society. DOI: 10.1007/s11746-014-2505-3.
A high-throughput, precipitating colorimetric sandwich ELISA microarray for shiga toxins - (Peer Reviewed Journal)
Gehring, A.G., He, X., Fratamico, P.M., Lee, J., Bagi, L.K., Brewster, J.D., Paoli, G., He, Y., Xie, Y., Skinner, C.B., Barnett, C., Harris, D. 2014. A high-throughput, precipitating colorimetric sandwich ELISA microarray for shiga toxins. Toxins. DOI: 10.3390/toxins6061855.
New high-affinity monoclonal antibodies against Shiga toxin 1 facilitate the detection of hybrid Stx1/Stx2 in vivo - (Peer Reviewed Journal)
Skinner, C.B., Patfield, S.A., Stanker, L.H., Fratamico, P.M., He, X. 2014. New high-affinity monoclonal antibodies against Shiga toxin 1 facilitate the detection of hybrid Stx1/Stx2 in vivo. PLoS One. 9(6):e99854. DOI:10.1371journal.pone0099854.
Current technologies for detection of ricin in different matrices - (Book / Chapter)
He, X. 2014. Current technologies for detection of ricin in different matrices.Cherwonogrodky, J.W., editor. Ricin Toxin. Oak Park, Illinois:Bentham Science. p. 38-56.
Risk of ricin from commercial castor production in North America - (Book / Chapter)
Auld, D.L., Trostle, C.L., Miller, T.D., He, X., Duncan, R.W. 2014. Risk of ricin from commercial castor production in North America. Cherwonogrodky, J.W., editor. Ricin Toxin. Oak Park, Illinois:Bentham Science. p. 86-97.
Safe and effective means of detecting and quantitating Shiga-like toxins in attomole amounts - (Peer Reviewed Journal)
Silva, C.J., Erickson-Beltran, M.L., Skinner, C.B., Dynin, I., Hui, C., Patfield, S.A., Carter, J.M., He, X. 2014. Safe and effective means of detecting and quantitating Shiga-like toxins in attomole amounts. Analytical Chemistry. DOI:10.1021/ac402930r.
Electron-beam is effective in reducing Escherichia coli on blueberries and extending the shelf life of the fruits - (Peer Reviewed Journal)
Kong, Q., Wu, A., Qi, W., Qi, R., Carter, J.M., Rasooly, R., He, X. 2014. Electron-beam is effective in reducing Escherichia coli on blueberries and extending the shelf life of the fruits. Postharvest Biology and Technology. 95(2014):28-35.
Using mass spectrometry to detect and discriminate among Shiga-like toxins in the attomole range. - (Abstract Only)
Silva, C.J., Erickson-Beltran, M.L., Skinner, C.B., Dynin, I.A., Hui, C., Patfield, S.A., He, X. 2014. Using mass spectrometry to detect and discriminate among Shiga-like toxins in the attomole range [abstract]. Meeting Abstract. Innovations in Mass Spectrometry. Paper No. 355.
Microwave heating inactivates Shiga Toxin (Stx2) in pH 7.4 buffer and in reconstituted fat-free Milk and adversely affects the nutritional value of cell culture medium - (Peer Reviewed Journal)
Rasooly, R., Hernlem, B.J., He, X., Friedman, M. 2014. Microwave heating inactivates Shiga Toxin (Stx2) in pH 7.4 buffer and in reconstituted fat-free Milk and adversely affects the nutritional value of cell culture medium. Journal of Agricultural and Food Chemistry. 62:3301-3305 DOI.org/10.1021/jf500278a.
Mouse in vivo neutralization of Escherichia coli Shiga toxin 2 with monoclonal antibodies - (Peer Reviewed Journal)
Cheng, L.W., Henderson II, T.D., Patfield, S.A., Stanker, L.H., He, X. 2013. Mouse in vivo neutralization of Escherichia coli Shiga toxin 2 with monoclonal antibodies. Infection and Immunity. 5:1845-1858. DOI: 10.3390/toxins5101845.
Development of monoclonal antibodies and immunoassays for sensitive and specific detection of Shiga Toxin Stx2f - (Peer Reviewed Journal)
Skinner, C.B., Patfield, S.A., Stanker, L.H., He, X. 2013. Development of monoclonal antibodies and immunoassays for sensitive and specific detection of Shiga Toxin Stx2f. PLoS One. 8(9):e76563 DOI: 10.1371/journal/pone.0076563.
A polyclonal antibody based immunoassay detects seven subtypes of Shiga toxin 2 produced by escherichia coli in human and environmental samples - (Peer Reviewed Journal)
He, X., Patfield, S.A., Hnasko, R.M., Rasooly, R., Mandrell, R.E. 2013. A polyclonal antibody based immunoassay detects seven subtypes of Shiga toxin 2 produced by escherichia coli in human and environmental samples. PLoS One. 8(10):e76368. DOI:10.1371/journal.pone.0076368.
Non-linear relationships between aflatoxin B1 levels and the biological response of monkey kidney vero cells - (Peer Reviewed Journal)
Rasooly, R., Hernlem, B.J., He, X. 2013. Non-linear relationships between aflatoxin B1 levels and the biological response of monkey kidney vero cells. Toxins. 5:1447-1461. doi:10.3390/toxins5081447.
Purification and characterization of Shiga toxin 2f, an immunologically unrelated subtype of Shiga toxin 2 - (Peer Reviewed Journal)
Skinner, C.B., Mcmahon, S.A., Rasooly, R., Carter, J.M., He, X. 2013. Purification and characterization of Shiga toxin 2f, an immunologically unrelated subtype of Shiga toxin 2. PLoS One. 8(3):e59760. doi:10.1371/journal.pone.0059760.
Development and characterization of monoclonal antibodies against Shiga toxin 2 and their application for toxin detection in milk - (Peer Reviewed Journal)
He, X., Mcmahon, S.A., Skinner, C.B., Merrill, P.A., Scotcher, M., Stanker, L.H. 2013. Development and characterization of monoclonal antibodies against Shiga toxin 2 and their application for toxin detection in milk. Journal of Immunological Methods. 389(1-2):18-28. doi:10.1016/j.jim.2012.12.005.
Reducing the toxicity of castor seed meal through processing treatments - (Peer Reviewed Journal)
McKeon, T.A., Shim, K., He, X. 2012. Reducing the toxicity of castor seed meal through processing treatments. Biocatalysis and Agricultural Biotechnology. doi.org/10.1016/j.bcab.2012.12.001.
A review on the challenges for increassed production of castor - (Review Article)
Severino, L.S., Auld, D.L., Baldanzi, M., Chen, G.Q., He, X., Crosby, W., Machado, O.L., Morris, J.B., Zieler, H. 2012. A review on the challenges for increassed production of castor. Agronomy Journal. 104(4):853-880.
Replacement of animals in assays for detection of toxins in food(Abstract) - (Abstract Only) - (10-Jul-12)
Detoxification of castor meal through reactive seed crushing - (Peer Reviewed Journal)
Dubois, J., Piccirilli, A., Magne, J., He, X. 2012. Detoxification of castor meal through reactive seed crushing. Industrial Crops and Products. 43(1):194-199.
Milk inhibits the biological activity of ricin - (Peer Reviewed Journal)
Rasooly, R., He, X., Friedman, M. 2012. Milk inhibits the biological activity of ricin. Journal of Biological Chemistry. 287(33):27924-27929. doi:10.1074/jbc.M112.362988.
A single-step purification and molecular characterization of functional Shiga toxin 2 variants from pathogenic Escherichia coli - (Peer Reviewed Journal)
He, X., Quinones, B., Mcmahon, S.A., Mandrell, R.E. 2012. A single-step purification and molecular characterization of functional Shiga toxin 2 variants from pathogenic Escherichia coli. Toxins. 4(7):487-504. doi:10.3390/toxins4070487
Sensitive bioassay for detection of biologically active ricin in food - (Peer Reviewed Journal)
Rasooly, R., He, X. 2012. Sensitive bioassay for detection of biologically active ricin in food. Journal of Food Protection. 75(5):951-954.
Evaluation and comparison of three enzyme-linked immunosorbent assay formats for the detection of ricin in milk and serum - (Peer Reviewed Journal)
He, X., Mcmahon, S.A., Rasooly, R. 2012. Evaluation and comparison of three enzyme-linked immunosorbent assay formats for the detection of ricin in milk and serum. Biocatalysis and Agricultural Biotechnology. 1(2):105-109. doi:10.1016/j.bcab.2011.08.016.
Sensitive detection of Shiga toxin 2 and some of its Stx 2 variants in environmental samples by a novel immuno-PCR assay - (Peer Reviewed Journal)
He, X., Qi, W., Quinones, B., Mcmahon, S.A., Cooley, M.B., Mandrell, R.E. 2011. Sensitive detection of Shiga toxin 2 and some of its Stx 2 variants in environmental samples by a novel immuno-PCR assay. Applied and Environmental Microbiology. 77(1):3558-3564. doi:10.1128/AEM.02205-10.
Ricin toxicokinetics and its sensitive detection in mouse sera or feces using immuno-PCR - (Peer Reviewed Journal)
He, X., Mcmahon, S.A., Henderson II, T.D., Griffey, S.M., Cheng, L.W. 2010. Ricin toxicokinetics and its sensitive detection in mouse sera or feces using immuno-PCR. PLoS One. 5(9):e12858. doi:10.1371/journal.pone.0012858.
Development of a Novel Immuno-PCR Assay for Detection of Ricin in Ground Beef, Liquid Chicken Egg and Milk - (Peer Reviewed Journal)
He, X., McMahon, S.A., McKeon, T.A., Brandon, D.L. 2010. Development of a Novel Immuno-PCR Assay for Detection of Ricin in Ground Beef, Liquid Chicken Egg and Milk. Journal of Food Protection. 73(4):695-700
Simple method to detect triacylglycerol biosynthesis in a yeast-based recombinant system - (Peer Reviewed Journal)
Siloto, R.M., Truksa, M., He, X., McKeon, T.A., Weselake, R. 2009. Simple method to detect triacylglycerol biosynthesis in a yeast-based recombinant system. Lipids. 44:963-973.
Detection of Protein Toxins - (Abstract Only)
Brandon, D.L., Cheng, L.W., He, X., Rasooly, R., Scotcher, M.C., Stanker, L.H., Carter, J.M. 2009. Detection of Protein Toxins. Meeting Abstract. Poster No. 8.
Validation of a Cell-Free Translation Assay for Detecting Shiga Toxin 2 in Bacterial Culture - (Peer Reviewed Journal)
He, X., Quinones, B., Carter, J.M., Mandrell, R.E. 2009. Validation of a Cell-Free Translation Assay for Detecting Shiga Toxin 2 in Bacterial Culture. Journal of Agriculture and Food Chemistry. 57(11):5084-5088
Immunochemical technologies for replacement of rodent bioassays in sensitive detection of toxins in foods - (Proceedings)
Carter, J.M., Cheng, L.W., He, X., Rasooly, R., Brandon, D.L., Stanker, L.H. 2010. Immunochemical technologies for replacement of rodent bioassays in sensitive detection of toxins in foods. Proceedings from Biodetection Technologies 6th Edition. 5:75-95.
Global challenges/chemistry solutions: Promoting personal safety and national security - (Popular Publication) - (02-Jul-08)
Effect of food matrices on the biological activity of ricin - (Peer Reviewed Journal)
He, X., Lu, S.S., Cheng, L.W., Rasooly, R., Carter, J.M. 2008. Effect of food matrices on the biological activity of ricin. Journal of Food Protection 71(10):2053-2058.
Detection of botulinum neurotoxin-A activity in food by peptide cleavage assay - (Peer Reviewed Journal)
Rasooly, R., Stanker, L.H., Carter, J.M., Do, P.M., Cheng, L.W., He, X., Brandon, D.L. 2008. In vitro peptide cleavage assay for detection of Botulinum Neurotoxin-A activity in food. International Journal of Food Microbiiology. 126 (2008):135-139
Ricinus communis contains and acyl-CoA synthetase that preferentially activates ricinoleate to its CoA thioester - (Peer Reviewed Journal)
He, X., Chen, G.Q., Kang, S.T., Mckeon, T.A. 2007. Ricinus communis contains and acyl-CoA synthetase that preferentially activates ricinoleate to its CoA thioester. Lipids Journal. 42:931-938.
Application of a real time PCR method to detect castor toxin contamination in fluid milk and eggs - (Peer Reviewed Journal)
He, X., Carter, J.M., Brandon, D.L., Cheng, L.W., Mckeon, T.A. 2007. Application of a real time PCR method to detect castor toxin contamination in fluid milk and eggs. Journal of Agricultural and Food Chemistry. 55:6897-6902
Molecular Approaches for the Identification of Toxin in Foods - (Abstract Only) - (23-Feb-07)
Synthesis of Novel Acylglycerol Substrates for Acyltransferases. - (Abstract Only)
McKeon, T.A., Kang, S., He, X., Lin, J.T., Turner, C. 2007. Synthesis of Novel Acylglycerol Substrates for Acyltransferases.. Proceedings JOCS/AOCS World Congress.
Expression Profiles of Genes Involved in Fatty Acid and Triacyblycerol Synthesis in Castor Bean (Ricinus communis L.) - (Peer Reviewed Journal)
Chen, G.Q., Turner, C., He, X., Nguyen, T.T., McKeon, T.A., Chingcuanco, D.L. 2007. Expression Profiles of Genes Involved in Fatty Acid and Triacyblycerol Syntheses in Castor Bean (Ricinus communis L.). Lipids. 41:263-274.
Detection of castor contamination by real-time polymerase chain reaction - (Peer Reviewed Journal)
He, X., Brandon, D.L., Chen, G.Q., McKeon, T.A., Carter, J.M. 2007. Detection of castor contamination by real-time polymerase chain reaction. Journal of Agricultural and Food Chemistry. 55(2):545-550.
Castor oil: Biosynthesis and Uses - (Abstract Only)
Mckeon, T.A., He, X., Chen, G.Q., Lin, J.T. 2007. Castor oil: Biosynthesis and Uses. 226th American Chemical Society National Meeting.
The Enzymology of Castor Oil Biosynthesis - (Abstract Only)
McKeon, T.A., He, X., Chen, G.Q., Lin, J.T. 2006. The Enzymology of Castor Oil Biosynthesis. Association for the Advancement of Industrial Crops Conference.
Bioavailability of Crude Ricin in Food Matrices - (Abstract Only)
Cheng, L.W., Brandon, D.L., He, X., Chen, G.Q., Carter, J.M. 2006. Bioavailability of crude ricin in food matrices. [Abstract]. ACS National Meeting and Exposition. Poster AGFD 64
Development of Monoclonal Antibodies Specific for Ricin - (Abstract Only)
Brandon, D.L., Cheng, L.W., He, X., Carter, J.M. 2006. Development of monoclonal antibodies specific for ricin. [Abstract]. ACS National Meeting and Exposition. Oral Presentation AGRO 234
Detection of Castor Contamination in Ground Beef by Real-Time Pcr - (Abstract Only)
He, X., Brandon, D.L., Chen, G.Q., Mckeon, T.A., Carter, J.M. 2006. Detection of castor contamination in ground beef by real-time pcr. [Abstract]. ACS National Meeting and Exposition. Poster AGFD 18.
Diacylglycerol Acyltransferase Activity and Triacylglycerol Synthesis in Germinating Castor Seed Cotyledons - (Peer Reviewed Journal)
He, X., Chen, G.Q., Lin, J.T., Mckeon, T.A. 2006. Diacylglycerol acyltransferase activity and triacylglycerol synthesis in germinating castor seed cotyledons. Lipids. Vol. 41, Number 3: 281-285, 2006.
Toward the Development of a Safe Castor Crop: Expression Pattern Comparison of Ricin and 2s Albumin Genes and Phylogeny Analysis of 2s Albumins - (Peer Reviewed Journal)
Chen, G.Q., He, X., Ahn, Y., Vang, L., Mckeon, T.A. 2006. Toward the development of a safe castor crop: expression pattern comparison of ricin and 2s albumin genes and phylogeny analysis of 2s albumins. Recent Progress in Medicinal Plants. 15: pp. 453-463
Selective Hydrolysis of Polar Triacylglycerols by Lipases - (Abstract Only)
McKeon, T.A., Kang, S., Turner, C., He, X., Lin, J.W. 2005. Selective Hydrolysis of Polar Triacylglycerols by Lipases. Pacifichem Symposium.
Castor Oil Boisynthesis and Expression Profiles of Lipid Genes in Developing Seed of Ricinus Communis L. (Castor Bean) - (Abstract Only)
Chen, G.Q., Turner, C., He, X., Mckeon, T.A. 2005. Castor oil boisynthesis and expression profiles of lipid genes in developing seed of ricinus communis l. (castor bean). Meeting Abstract.
Quantitative Transcript Profiling of Lipid Biosynthesis Genes in Developing Castor Seeds. - (Abstract Only)
Chen, G.Q., Ahn, Y., He, X., Mckeon, T.A. 2005. Quantitative transcript profiling of lipid biosynthesis genes in developing castor seeds.. National Plant Lipid Cooperative Meeting.
Endosperm Morphology and Transcript Profiles of Storage Proteins in Developing Castor Seeds. - (Abstract Only)
Chen, G.Q., Ahn, Y., He, X., Mckeon, T.A. 2005. Endosperm morphology and transcript profiles of storage proteins in developing castor seeds.. World Congress on In Vitro Biology.
Molecular Characterization of the Acyl-Coa-Dependent Diacylglycerol Acyltransferase in Plants - (Review Article)
He, X., Chen, G.Q., Lin, J.T., Mckeon, T.A. 2005. Molecular characterization of the acyl-coa-dependent diacylglycerol acyltransferase in plants. Research Signpost: Recent Research Developments in Applied Microbiology and Biotechnology. 2:69-86.
Effect of Diacylglycerol Acyltransferase on Lipid Metabolism in Developing Seeds of Castor - (Abstract Only)
He, X., Chen, G.Q., Lin, J.T., Mckeon, T.A. 2005. Effect of diacylglycerol acyltransferase on lipid metabolism in developing seeds of castor. Annual Meeting and Expo of the American Oil Chemists' Society.
A Simple and Sensitive Assay for Distinguishing the Expression of Ricin and Ricinus Communis Agglutinin Gene in Developing Castor Seed (Ricinus Communis L.) - (Peer Reviewed Journal)
Chen, G.Q., He, X., McKeon, T.A. 2005. A simple and sensitive assay for distinguishing the expression of ricin and ricinus communis agglutinin gene in developing castor seed (Ricinus communis L.). Journal of Agricultural and Food Chemistry. 53(6):2358-2361.
2s Albumin Gene Expression in Castor Plant (Ricinus Communis L.) - (Peer Reviewed Journal)
Chen, G.Q., He, X., Liao, L., McKeon, T.A. 2004. 2s Albumin Gene Expression in Castor Plant (Ricinus communis L.). Journal of the American Oil Chemists' Society. 81(9):867-872.
Cloning and Characterization of Castor Dgat - (Peer Reviewed Journal)
He, X., Chen, G.Q., Lin, J.T., Mckeon, T.A. 2004. Cloning and characterization of castor dgat. Lipids Journal.39:311-318
Application of Lipases to Develop Novel Acyltransferase Substrates - (Proceedings)
Mckeon, T.A., Turner, C., He, X., Chen, G.Q., Lin, J.T. 2003. Application of lipases to develop novel acyltransferase substrates. Meeting Abstract.
Last Modified: 10/21/2014
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