A Detection Method of CryIAc Protein for Identifying Genetically Modified Rice Using the Lateral Flow Strip Assay

Abstract

We examined the lateral flow strip assay for identifying unauthorized genetically modified (GM) rice. The GM rice expresses the Bacillus thuringiensis (Bt) toxin, CryIAc protein, which confers tolerance to insects. The recombinant CryIAc protein was prepared from the inclusion bodies of an E. coli. strain into which the CryIAc gene had been inserted, using gel filtration chromatography. The lateral flow strip assay for the identification of GM cotton which also expresses CryIAc protein, was applied to unpolished rice and polished rice spiked with recombinant CryIAc protein. The spiked recombinant CryIAc protein was clearly detected at the level of 0.012 mg/g in both the unpolished and polished rice. After loading of the extract on the strip, a 60 -minute stand time is necessary to clearly detect CryIAc protein. The detection limit was approximately 12 ng CryIAc protein per gram of rice. These results suggest that the lateral flow strip assay for GM cotton can be used to detect CryIAc protein expressed in GM rice.

Surface Plasmon Resonance Detection of Transgenic Cry1Ac Cotton (Gossypium spp.)

“…Separately, the two techniques offer high specificity and simple operation. , To detect the targeting protein in GMOs, the most preferred immunoassay is a sandwich ELISA, which needs two specific antibodies with high affinity per one analyte. , It is laborious and time-consuming to develop a successful ELISA method for the detection of novel protein expressed in transgenic crops. However, the SPR assay allows for the sensitive detection of target analyte using only one antibody with low or high affinity in a label-free environment. − The lateral flow strips method was adopted to detect Cry1Ac protein in rice, which can provide a yes/no determination within 5–10 min . However, commercially available lateral flow strips are currently limited to a few biotechnology-derived GM proteins.…”

“…Separately, the two techniques offer high specificity and simple operation. 18,19 To detect the targeting protein in GMOs, the most preferred immunoassay is a sandwich ELISA, which needs two specific antibodies with high affinity per one analyte. 12,27 It is laborious and time-consuming to develop a successful ELISA method for the detection of novel protein expressed in transgenic crops.…”

“…28−30 The lateral flow strips method was adopted to detect Cry1Ac protein in rice, which can provide a yes/no determination within 5−10 min. 19 However, commercially available lateral flow strips are currently limited to a few biotechnology-derived GM proteins. Compared with these two methods, the proteinbased SPR detection scheme described herein was more timesaving in experimental operation and exhibited a wider range of applications.…”

“…Western blotting is the most accurate of these detection methods, and it can identify the size of the protein expressed in the transgenic materials . ELISAs and lateral flow strips are the most widely used techniques in GMO identification. , The sandwich ELISA format has been employed to detect novel proteins in GMOs for its features of high sensitivity and specificity, which are induced by enzymatic substrate reaction and antibody–antigen interaction, separately. The lateral flow format, which is a variation on ELISA, using strips rather than microtiter wells, is rapid and simple and does not require the use of specialized equipment.…”

Indicated Detection of Two Unapproved Transgenic Rice Lines Contaminating Vermicelli Products

“…To date, Bt crops of cotton (), maize (), and potatoes () that have insect resistance have been commercialized in some countries, including Japan ( , ). However, no developed Bt rice has yet been authorization for food use in the European Union, Korea, and Japan ( − ).…”