Foodprint® Indicator - Technical Literature
The Foodprint® Indicator Test utilizes basically the same technology as the Foodprint® 40, 60, 120 and 200+. The Genarrayt® Food IgG test is a rapid colorimetric microarray-based ELISA for the measurement of IgG antibodies for up to 221 foods in whole blood, human serum or plasma. Genarrayt® Microarray Food IgG technology has been developed by our sister company Genesis Diagnostics Ltd. For further information visit www.elisa.co.uk
Explanation of the Test
Many people exhibit chronic food sensitivity reactions to specific food antigens. Unlike the immediate effects of IgE-mediated allergy, IgG-mediated food sensitivity reactions may take several days to appear. Controlled removal of the problem foods from the patient’s diet will, in many cases, rapidly improve the patient’s condition. General lethargy, weight gain, dermatitis, arthritis and tiredness are associated with food intolerances. Irritable bowel syndrome may also be linked to food sensitivity.
Principle of the test
Up to 221 foods are microarrayed onto each of 16 nitrocellulose pads on a glass microscope slide. Non-specific binding sites are blocked with blocking buffer prior to incubation with diluted patient whole blood, serum or plasma. After washing away unbound serum components, anti-human IgG conjugated to horseradish peroxidase is added to the pads, and this binds to food extract-bound antibodies in the second incubation. Unbound conjugate is removed by washing, and a solution containing 3,3’,5,5’-tetramethylbenzidine (TMB) and enzyme substrate is added to trace specific antibody binding. After washing with distilled water, the slides are dried by centrifugation prior to scanning.The optical densities of the standards, positive and negative controls and samples are measured using a high resolution flat bed scanner with associated software.Optical density is directly proportional to antibody activity in the sample.