Novel ELISA for the detection of raw and processed egg using extraction buffer containing a surfactant and a reducing agent

Enzyme-linked immunosorbent assay (ELISA) has been considered extremely useful for the detection of markers of allergenic substances in food, because it is simple, offers a suitable sensitivity, and is useful in providing quantitative results. Allergenic protein present in processed food can be denatured or altered, hindering therefore their possibility to be extracted and detected. This paper reports the development of an ELISA method that can be used for the determination of allergenic proteins in buffer solutions containing SDS, a surfactant, and 2-mercaptoethanol, a reducing agent. Measurement by ELISA in solutions containing 1% SDS and 7% 2-mercaptoethanol has been made possible by using an antibody prepared through immunization with an antigen denatured with SDS and 2-mercaptoethanol. This ELISA technique can be used to measure proteins in food that have been denatured by various manufacturing processes. An example is egg white albumin, which is susceptible to heat denaturation and has been difficult to recover from food in the past. Its recovery was improved 10- to 100-fold by the new ELISA method as compared with previous methods. This means that allergenic substances in food can now be detected quantitatively. This method can be very useful in allergy prevention and control strategies. (c) 2005 Elsevier B.V All rights reserved.