(ELISA) to Detect Trace Amounts of Almond (Prunus Dulcis L.) Mengna Su
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Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2012 Development of a Specific, Sensitive, and Robust Enzyme-Linked Immunosorbent Assay (ELISA) to Detect Trace Amounts of Almond (Prunus Dulcis L.) Mengna Su Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF HUMAN SCIENCES DEVELOPMENT OF A SPECIFIC, SENSITIVE, AND ROBUST ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA) TO DETECT TRACE AMOUNTS OF ALMOND (PRUNUS DULCIS L.) By MENGNA SU A Dissertation submitted to the Department of Nutrition, Food and Exercise Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy Degree Awarded: Spring Semester, 2012 Mengna Su defended this dissertation on March 15, 2012. The members of the supervisory committee were: Shridhar K. Sathe Professor Directing Dissertation William T. Cooper III University Representative Yun-Hwa Peggy Hsieh Committee Member Jodee Dorsey Committee Member Mary Ann Moore Committee Member The Graduate School has verified and approved the above-named committee members, and certifies that the dissertation has been approved in accordance with university requirements. ii To my parents, Xingqing Su (苏兴庆) and Qianhua Chen (陈倩华); my husband, Jinqing Xie (谢 锦清); my daughter, Yier Xie (谢漪儿); my brother and sister. iii ACKNOWLEDGEMENTS I believe I will never come to this point without the help of many brilliant and immensely supportive people. Special thanks to my major professor, Dr. Shridhar K. Sathe, for providing the opportunity to work in his lab in NFES at FSU, for suggesting research direction, for instructing in person of key lab skills, for the excellent and quality scientific instruments and materials made available, for the freedom in pursuing my research interest, and for the tough four years and eight months training…I would like to deeply thank Dr. Yun-Hwa Peggy Hsieh for serving in my committee, providing me guidance, and teaching me basics of immunoassay. I also thank Dr. Mary Ann Moore, Dr. Jodee Dorsey and Dr. William T. Cooper for serving in my committee, providing valuable inputs, and supporting me throughout this program. Thanks to Drs. Bahram Arjmandi, Yun-Hwa Peggy Hsieh and Jeong-Su Kim for allowing me use their lab instruments to assist my research. Thanks to Ms. Margaret Seavy and Dr. Giordano Fiore at the analytical facilities of Dept. of Biological Science for their help in protein N-terminal sequencing. I sincerely thank College of Human Sciences and the Department of Nutrition, Food, and Exercise Sciences for providing the opportunity and financial support to pursue my doctoral degree. Funds from the USDA-AFRI (2009-65503-05797 & 2011-67017-20079), Washington, DC; Almond Board of California, Modesto, CA; the Florida State University Research Fundation Grant Assistance Program (GAP) grant, Tallahassee, FL; the Florida State University Dissertation Research Grant (DRG), Tallahassee, FL; and College of Human Sciences Dissertation Award Program (DAP), Tallahassee, FL are greatly appreciated. Many thanks to Dr. Mary Ann Moore, Dr. Bahram Arjmandi, Ms. Marian Sumner, Ms. Regina Fassig and the administrative personnel, Ms. Tara Hartman, Ms. Ann Smith, Mr. David Parish, Mr. Joseph Carroll, Ms. Barbara Koehler, Ms. Jeannine Spears, Mr.Andy Zimmerman, and Mr.General Gaskin for always being there to help!! My labmates, Mahesh, Harshal, Girdhari, Mimi, Shyamali, Ying, Changqi and Sahil; and LeAnna from Dr. Roux’s lab are greatly thanked for their research support and making work in the lab very joyful. Special thanks to Shyamali, Haiyan, Changqi, Ying, and Sophie for their great help in the preparation of dissertation and defense! I am deeply thankful to Pei-yang, iv Sheauching, Haiyan, and Bi-jen for accompanying me through this period and helping me out always!! I enjoy friendship from Qinchun, Anuri, Yi-tien, Michael, Kamil, Jack, Florence, Dr. Shim, Nancy, Quanhong, Sophie, Shirin, Raz, Abbey, Jiyao, Marcus, Rafaela, Zahra, Liza, Jenna, Ajay, Alexei, and Monica. My friends, Haihong, Jingfang, Xu hui and their families, and Xiaoli, thank you for all the happiness you brought to me! Finally, all my endeavors are dedicated to my parents, my daughter, and my husband for their constant and endless love, encouragement and support. Special sorry goes to Yier for the invisible mom whom is always “in” the window of “google talk” or at the other end of telephone line… v TABLE OF CONTENTS List of Tables ...................................................................................................................................x List of Figures ............................................................................................................................... xii List of Terms and Abbreviations ................................................................................................ xiv Abstract ...................................................................................................................................... xviii 1. INTRODUCTION ...................................................................................................................1 1.1 Background and Significance ........................................................................................1 1.1.1 Almond ..............................................................................................................1 1.1.2 Allergy and Tree Nut Allergy ............................................................................3 1.1.3 Almond Allergens and Almond Allergy ............................................................6 1.1.4 Need for Food Allergen Detection Methods ....................................................10 1.1.5 Available Almond Detection Methods ............................................................13 1.2 Statement of Problem ...................................................................................................17 1.3 Central Hypothesis .......................................................................................................18 1.4 Specific Aims ...............................................................................................................18 2. PURIFICATON AND CHARACTERIZATION OF ANTI-ALMOND SOLUBLE PROTEIN MURINE MONOCLONAL ANTIBODIES ...............................................................20 2.1 Materials and Methods .................................................................................................22 2.1.1 Materials ..........................................................................................................22 2.1.2 Methods............................................................................................................24 2.1.2.1 Antibody Production and Screening of mAbs ...................................24 2.1.2.2 Preparation of Protein Extracts ..........................................................24 2.1.2.3 Protein Determination ........................................................................25 2.1.2.4 Antibody Purification.........................................................................25 2.1.2.5 SDS PAGE with CBBR Staining .......................................................26 2.1.2.6 Silver Staining ....................................................................................26 2.1.2.7 Standardization of Purified mAb .......................................................27 2.2.2.7.1 IgG Concentration .............................................................27 2.2.2.7.2 Ab Titer .............................................................................27 2.2.2.7.3 Ag Titer .............................................................................27 2.1.2.8 Epitope Comparison and Antigen Identification ...............................27 2.2.2.8.1 Indirect ELISA ..................................................................27 2.2.2.8.2 ELISA Additivity Test ......................................................28 2.2.2.8.3 Column Chromatography..................................................29 2.2.2.8.4 Non-denaturing Non-dissociating-Polyacrylamide Gel Electrophoresis (NDND PAGE) .......................................................29 2.2.2.8.5 Western Blotting ...............................................................30 2.2.2.8.6 Molecular Weight (MW) Determination by SDS PAGE .30 2.2.2.8.7 Cyanogen Bromide (CNBr) Affinity Chromatography ....31 2.2.2.8.8 N-terminal Amino Acid Sequencing ................................31 2.1.2.9 Statistical Analysis .............................................................................32 2.2 Results and Discussion ................................................................................................32 2.2.1 Antibody Production and Screening of mAbs .................................................32 2.2.2 Antibody Purification.......................................................................................32 2.2.3 Standardization of Purified mAbs ....................................................................34 vi 2.2.4 Epitope Comparison and Antigen Identification .............................................40 2.3.4.1 ELISA additivity test .........................................................................40 2.3.4.2 Column Chromatography...................................................................40 2.3.4.3 Molecular Weight (MW) Determination by SDS PAGE ..................48