Validation of an immunoassay for detection and quantitation of a genetically modified soybean in food and food fractions using reference materials: interlaboratory study.
An immunoassay for detection of a specific genetically modified soybean (Roundup-Ready) was validated on dried soybean powder in an interlaboratory study. Different percentages of genetically modified soybeans in nonmodified soybean matrix were evaluated in a blind study. Thirty-eight laboratories from 13 countries participated. The immunoassay was evaluated for 2 endpoints: (1) To give a semiquantitative result, i.e., determination of a given sample above or below a given threshold, or (2) to compute a quantitative result, i.e., percentage of genetically modified soybeans in the sample. Semiquantitative results showed that a given sample which contained <2% genetically modified soybeans was identified as below 2% with a 99% confidence level. Quantitative use of the assay resulted in a repeatability (r) and reproducibility (R) that were computed to be RSDr = 7% and RSDR = 10%, respectively, for a sample containing 2% genetically modified soybeans. Application of this method depends on availability of appropriate reference materials for a specific food matrix. Only matrix-matched reference materials can be used for analysis of food or food fractions.
Lipp
M
M
European Commission, Joint Research Center, Institute for Health and Consumer Protection, Food Products and Consumer Goods Unit, Ispra (Va), Italy.
Anklam
E
E
Stave
J W
JW
Lipp
M
M
Anklam
E
E
Stave
J W
JW
D000911:Antibodies, Monoclonal; D002138:Calibration; D005504:Food Analysis / Q000379:methods*; D005818:Genetic Engineering; D007118:Immunoassay; D007391:International Cooperation; D007753:Laboratories; D016015:Logistic Models; D011786:Quality Control; D011933:Reagent Kits, Diagnostic; D012015:Reference Standards; D012680:Sensitivity and Specificity; D013025:Glycine max / Q000737:chemistry / Q000235:genetics*
D000911:Antibodies, Monoclonal; D011933:Reagent Kits, Diagnostic