Abstract:

In this research, processed or low processed samples containing corn or corn products (corn semolina, flour, etc.) and soybean were randomly collected from the market, and 25 products in total (chips, nuts, cereals, flour) were analyzed for genetic modification using DNA based detection method, the polymerase chain reaction. First, homogenization of the samples was performed. Then DNA isolation was done by using Cetyl Trimethyl Ammonium Bromide (CTAB) and Roche High Pure DNA Isolation Kit. Since the Roche High Pure DNA Isolation Kit gave better results, the analysis was completed with this method. After DNA isolation, the detection of the Lectin gene, Zein gene, CaMV 35S Promoter and NOS Terminator regions was performed by conventional PCR. Zein gene determination was done for searching and proving corn presence and similarly, Lectin gene determination was done for searching and proving soybean presence in the samples by conventional PCR. GMO3/GMO4 and Zein3/Zein4 primer pairs were used for Lectin and Zein gene determination, respectively. The amplification of DNA was observed in agarose gel electrophoresis. Lectin or Zein genes were detected in 17 samples while these genes were not detected in 8 samples. Samples, in which Lectin or Zein gene was detected were scanned for 35S promoter or NOS terminator. 35S-3/35S-6 and tNOS2F/tNOS2R primer pairs were used for scanning 35S Promoter and NOS Terminator, respectively. To observe possible contamination in the mix sterilized deionized water was used and 0% Bt-11 and 0% GTS 40-3-2 were used as a negative control, 5% Bt-11 and 10% GTS-40-3-2 were used as a positive control. All of the 25 samples did not provide enough DNA with the required quality. This result was considered to be sourced by the applications (frying, extruding, pressing etc.) that samples had been exposed to during processes. Neither 35S Promotor nor NOS Terminator was determined from any of the samples.

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