title: Collaborative ring trial of the papaya endogenous reference gene and its polymerase chain reaction assays for genetically modified organism analysis.
abstract: The papaya (Carica papaya L.) Chymopapain (CHY) gene has been reported as a suitable endogenous reference gene for genetically modified (GM) papaya detection in previous studies. Herein, we further validated the use of the CHY gene and its qualitative and quantitative polymerase chain reaction (PCR) assays through an interlaboratory collaborative ring trial. A total of 12 laboratories working on detection of genetically modified organisms participated in the ring trial and returned test results. Statistical analysis of the returned results confirmed the species specificity, low heterogeneity, and single-copy number of the CHY gene among different papaya varieties. The limit of detection of the CHY qualitative PCR assay was 0.1%, while the limit of quantification of the quantitative PCR assay was ∼25 copies of haploid papaya genome with acceptable PCR efficiency and linearity. The differences between the tested and true values of papaya content in 10 blind samples ranged from 0.84 to 6.58%. These results indicated that the CHY gene was suitable as an endogenous reference gene for the identification and quantification of GM papaya.
authors.affiliation: National Center for Molecular Characterization of Genetically Modified Organisms, SJTU-Bor Luh Food Safety Center, School of Life Science and Biotechnology, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
authors.forename: Jiaojun
authors.initials: J
authors.lastname: Wei
authors.forename: Feiwu
authors.initials: F
authors.lastname: Li
authors.forename: Jinchao
authors.initials: J
authors.lastname: Guo
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Junfeng
authors.initials: J
authors.lastname: Xu
authors.forename: Gang
authors.initials: G
authors.lastname: Wu
authors.forename: Dabing
authors.initials: D
authors.lastname: Zhang
authors.forename: Litao
authors.initials: L
authors.lastname: Yang
mesh_terms: D029441:Carica / Q000235:genetics*; D002917:Chymopapain / Q000235:genetics; D018628:Gene Dosage; D057230:Limit of Detection; D030821:Plants, Genetically Modified / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D015203:Reproducibility of Results; D013045:Species Specificity
chemical_list: D002917:Chymopapain