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Detection of irradiated frozen food with the DNA comet assay: interlaboratory test
Author(s) -
Cerda Humberto
Publication year - 1998
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199803)76:3<435::aid-jsfa969>3.0.co;2-x
Subject(s) - comet assay , agarose , agarose gel electrophoresis , irradiation , microbiology and biotechnology , dna , dna damage , gel electrophoresis , comet , ionizing radiation , biology , chemistry , biochemistry , physics , astrobiology , nuclear physics
Ionising radiation induces DNA damage in the cells of the foodstuff. This fact was used to analyse DNA from single cells by agarose gel electrophoresis (DNA comet assay). The pattern formed by the DNA after electrophoresis (DNA comet) was visualised in a microscope, where hundreds of cells could be observed in a short time. Irradiated cells showed comets with long tails, while unirradiated cells showed no tail or very short ones. An estimation of the dose was made based on the shape of the comets. Nine laboratories, from Berlin, Berne, Chipping Campden, Karlsruhe, Copenhagen, Strasbourg, Uppsala and Warsaw, participated in a test to assess the validity of the method. The test material consisted of code‐labelled cell suspensions made of irradiated and unirradiated chicken bone marrow, chicken and pork muscle tissue. The doses varied between 0 and 5 kGy. Samples of chicken bone marrow were used as references. A total of 162 test samples were sent for analysis. Results of analysis from 148 samples were reported. Of these, 138 were correctly identified. Six laboratories succeeded in identifying all the samples. In the group of 106 irradiated samples, 99 were correctly detected, while 39 out of 42 unirradiated samples were correctly detected. It is concluded that the comet assay can be used to detect frozen irradiated food. © 1998 SCI.