Please cite this article in press as: Kamath, S.D., et al., Molecular and immunological approaches in quantifying the air-borne food allergen tropomyosin in crab processing facilities. Int. J. Hyg. Environ. Health (2014), http://dx.doi.org/10.1016/j.ijheh.2014.03.006 ARTICLE IN PRESS G Model IJHEH-12764; No. of Pages 11 International Journal of Hygiene and Environmental Health xxx (2014) xxx–xxx Contents lists available at ScienceDirect International Journal of Hygiene and Environmental Health jo u r n al homepage: www.elsevier.com/locate/ijheh Molecular and immunological approaches in quantifying the air-borne food allergen tropomyosin in crab processing facilities Sandip D. Kamath a,b , Marte R. Thomassen c,e , Shruti R. Saptarshi a,b , Hong M.X. Nguyen d , Lisbeth Aasmoe c,f , Berit E. Bang c,f , Andreas L. Lopata a,b,∗ a Molecular Immunology Group, School of Pharmacy and Molecular Science, James Cook University, Townsville, QLD, Australia b Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Townsville, QLD, Australia c Department of Occupational- and Environmental Medicine, University Hospital of North Norway, Tromsø, Norway d Faculty of Food Science and Technology, Nong Lam University, Ho Chi Minh City, Viet Nam e Department of Community Medicine, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway f Medical Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway a r t i c l e i n f o Article history: Received 27 January 2014 Received in revised form 8 March 2014 Accepted 8 March 2014 Keywords: Tropomyosin Allergen detection Occupational allergy Shellfish Sandwich ELISA Airborne allergen a b s t r a c t Tropomyosin is a cross-reactive allergenic protein present in ingested shellfish species. Exposure and sensitization to this protein via inhalation is particularly important in the crustacean processing industry where workers are continuously exposed to the aerosolized form of this allergen. The aim of this study was to develop an antibody-based immunoassay to enable the specific and sensitive quantification of aerosolized tropomyosin present in the environment of two crab processing facilities. Anti-tropomyosin antibody was generated in rabbits against tropomyosins from four different crus- tacean species. These antibodies were purified using recombinant tropomyosin using an immuno-affinity column. The recombinant tropomyosin was also used as an allergen standard for the sandwich ELISA. In order to quantify aerosolized tropomyosin, air collection was performed in the personal breathing zone of 80 workers during two crab processing activities, edible crab (Cancer pagurus) and king crab (Paralithodes camtschaticus) using polytetrafluoroethylene filters. The purified antibody was able to detect tropomyosin selectively from different crustaceans but not from vertebrate sources. The limit of detection (LOD) for the developed sandwich ELISA was 60 picogram/m 3 and limit of quantitation (LOQ) 100 picogram/m 3 . Immunoassay validation was based on linearity (R 2 0.999), matrix interference test (78.8 ± 6.5%), intra- assay CV (9.8%) and inter-assay CV (11%). The novel immunoassay was able to successfully identify working activities, which generated low, medium or high concentrations of the aerosolized food allergen. We describe an IgG antibody-based immunoassay for quantification of the major food allergen tropomyosin, with high sensitivity and specificity. This modified immunological approach can be adapted for the detection of other aerosolized food allergens, assisting in the identification of high-risk allergen exposure areas in the food industry. © 2014 Elsevier GmbH. All rights reserved. Abbreviations: Tm, tropomyosin; rTm, recombinant tropomyosin; cAb-TM, anti-tropomyosin capture antibody; dAb-TM, detection antibody. ∗ Corresponding author at: Molecular Immunology Group, School of Pharmacy and Molecular Science, Centre for Biodiscovery and Molecular Development of Thera- peutics, Building 21, Molecular Sciences, James Cook Drive, Douglas Campus, James Cook University, Townsville, QLD 4811, Australia. Tel.: +61 07 47814563; fax: +61 07 47816078. E-mail addresses: sandip.kamath@jcu.edu.au (S.D. Kamath), marte.renate.thomassen@unn.no (M.R. Thomassen), Shruti.saptarshi@jcu.edu.au (S.R. Saptarshi), nmxuanhong@yahoo.com (H.M.X. Nguyen), lisbeth.aasmoe@unn.no (L. Aasmoe), berit.bang@unn.no (B.E. Bang), andreas.lopata@jcu.edu.au (A.L. Lopata). Introduction Occupational allergy and asthma has become a serious health concern, especially for workers in the seafood industry. Increased global consumption and changing dietary habits have greatly facil- itated seafood production (Lopata and Jeebhay, 2013; Lopata and Lehrer, 2009). This in turn, has caused more workers to be exposed to seafood allergens on a daily basis. According to a report by the Food and Agriculture Organization (FAO) in 2010, nearly 45 mil- lion people are involved in seafood and aquaculture production. Several studies have shown that the prevalence of occupational asthma among workers exposed to shellfish is between 4% and 36% (Bonlokke et al., 2012; Granslo et al., 2009; Howse et al., 2006). Moreover, workers with occupational asthma to shellfish http://dx.doi.org/10.1016/j.ijheh.2014.03.006 1438-4639/© 2014 Elsevier GmbH. All rights reserved.