Biotech Updates

Collaborative Ring Trial of the Papaya Endogenous Reference Gene and Its PCR Assays for GMO Analysis

November 20, 2013

Previous studies have reported that the papaya (Carica papaya L.) Chymopapain (CHY) gene is a suitable endogenous reference gene for GM papaya detection. In a study conducted by Jiaojun Wei of Shanghai Jiao Tong University and other researchers, they further validated the use of the CHY gene and its qualitative and quantitative polymerase chain reaction (PCR) assays through an interlaboratory collaborative ring trial.

Twelve laboratories working on detection of GMOs participated in the ring trial. Statistical analysis of the returned results showed that 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 percent, 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 percent. Based on the results, CHY gene can be used an endogenous reference gene for the identification and quantification of GM papaya.

Read the research article for more details: http://pubs.acs.org/doi/abs/10.1021/jf403338a.