Interlaboratory validation study of an event-specific real-time polymerase chain reaction detection method for genetically modified 55-1 papaya.

Genetically modified (GM) papaya line 55-1 (55-1) is resistant to papaya ringspot virus infection, and is commercially available in several countries. A specific detection method for 55-1 is required for mandatory labeling regulations. An event-specific real-time PCR method was developed by our laboratory.

Application of a qualitative and quantitative real-time polymerase chain reaction method for detecting genetically modified papaya line 55-1 in papaya products.

Genetically modified (GM) papaya (Carica papaya L.) line 55-1 (55-1), which is resistant to papaya ringspot virus infection, has been marketed internationally. Many countries have mandatory labeling regulations for GM foods, and there is a need for specific methods for detecting 55-1.

Interlaboratory validation of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

To reduce the cost and time required to routinely perform the genetically modified organism (GMO) test, we developed a duplex quantitative real-time PCR method for a screening analysis simultaneously targeting an event-specific segment for GA21 and Cauliflower Mosaic Virus 35S promoter (P35S) segment [Oguchi et al., J. Food Hyg.

Qualitative PCR method for Roundup Ready soybean: interlaboratory study.

Quantitative and qualitative methods based on PCR have been developed for genetically modified organisms (GMO). Interlaboratory studies were previously conducted for GMO quantitative methods; in this study, an interlaboratory study was conducted for a qualitative method for a GM soybean, Roundup Ready soy (RR soy), with primer pairs designed for the quantitative method of RR soy studied previously. Fourteen laboratories in Japan participated.

[Selection of suitable polypropylene tubes for DNA testing using real-time PCR].

Polypropylene microtubes (tubes) are generally used for bio-material tests in addition to PCR tests such as genetically modified organism (GMO) testings. However, the choice of suitable tubes is quite important, because it might influence the results: DNA binding and/or elution of chemical substances sometimes occurs. In this study, we established methods to select tubes with the most suitable characteristics for DNA testing.

Development of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

A duplex real-time PCR method was developed for quantitative screening analysis of GM maize. The duplex real-time PCR simultaneously detected two GM-specific segments, namely the cauliflower mosaic virus (CaMV) 35S promoter (P35S) segment and an event-specific segment for GA21 maize which does not contain P35S. Calibration was performed with a plasmid calibrant specially designed for the duplex PCR.

Investigation of residual DNAs in sugar from sugar beet (Beta vulgaris L.).

Genetically modified (GM) sugar beets have been bred for use as food and animal feed. To evaluate the applicability of GMO analyses to beet sugar products, we investigated residual DNA in eight sorts of in-process beet sugar samples and commercial beet sugar products. Polymerase chain reaction (PCR) analyses with taxon-specific primers indicated that sugar beet DNA was degraded at an early stage of sugar processing, and no PCR amplification was detected from the investigated sugar products because of low DNA recovery and/or PCR inhibition.

Impaired function of dendritic cells in alymphoplasia (aly/aly) mice for expansion of CD25+CD4+ regulatory T cells.

Alymphoplasia (aly/aly) mice are from a naturally occurring strain with a mutation in nuclear factor-kappa B inducing kinase (NIK). The NIK mutation causes disruption of the architecture of the thymus and spleen and aly/aly mice show decreased numbers of CD25+CD4+T cells in the spleen. For the expansion of CD25+CD4+T cells, interactions between dendritic cells (DCs) and CD25+CD4+ regulatory T cells are necessary.