Identification of GMO foods using PCR - Lab Report Example

Running head: GMOs Identification of GMOs using PCR College: In the laboratory, we performed DNA isolation on food products (soy beans) and amplification of the DNA was done by polymerase chain reaction (PCR) on soy beans food DNA in order to detect the presence of genetic modification. The genetically modified reference standards were used as controls and the samples were analyzed using agarose gel electrophoresis. GMOs was not identified in all of our soy beans samples with PCR method, we rejected our null hypothesis that stated GMOs was present in our soy beans samples.

Introduction Genetically modified foods are ever appearing in the news. While on the other hand, genetic modifications have improved several crops that include increasing the yields. There are many groups of people who have raised protest against “tinkering” with crop plants (FDA. 2000). However, In the U.S.A., The introduction of these genetically modified foods to the market has been with little fanfare. Most parts of the world have been experiencing increasing and strong resistance to any genetically modified foods introduction to the market place.

The European Union together with other countries usually need certification on foods entering their countries and this should be Genetically Modified Organism (GMO) free ( DG JRC,1998). Testing of the food products is done to confirm the presence of GMOs. Occasionally, food contamination occurs or food testing is inaccurate and this results to the presence of GMOs in foods. PCR is one the methods used to test for GMOs in food products, whereby the band presence shows that there are GMOs. The PCR principle is to multiply specific DNA sequences, so that they can be detected.

This method that is highly sensitive offers the advantage to detect the molecules of DNA that are more thermo stable than proteins (Arakawa et al, 1998). The efficiency of confirmation, identification and screening strategies is supposed to be examined with respect to false-positive rates, increased use of specific regulator sequences, marker genes disappearance and the increasing GM foods in number (Clark et al, 2002). In the lab, the GMOs presence in conventional soy beans samples was tested by PCR.

The null hypothesis was; there is GMOs in the soy beans. Methods The experiment objective as indicated earlier was to use the PCR method to identify genetically modified foods in the soy beans. Firstly, the DNA was isolated from the soy beans samples. This was done by weighing about 50-100 mg of the sample and later it was transferred to a test tube. 400 ?l of extraction buffer was added to the tube then the tube contents were mashed with a micro-pestle. The test tubes were later incubated at 56°C for about an hour.

The test tubes were removed out and 300?l of NaCl solution was added. The contents of the tube were mixed for about 30 seconds by vortexing, later the tube was centrifuged for about 15-30 minutes. The supernatant was then removed from the tube. It was then transferred to a fresh tube. 100% isopropanol equal volume was added to the new test tube. This was incubated until the next lab period in the freezer. After this, the test tubes were spinned at 4°C for about 20 minutes. Later, the supernatant was removed from the pellet of which the pellet was washed appropriately with 1.

5 ml of 70% ethanol. The pellet was allowed to completely dry while the alcohol was discarded. The pellet of DNA was later dissolved in 300 ?l of 1xTE buffer, then placed on ice until the time the PCR was ready. The samples were then prepared for PCR; making sure the PCR reaction pellet was at the tube bottom and the tube was labeled. Preparation of PCR reaction mix was done by adding 5 ?l of DNA template for amplification and 20 ?l of primer mix was added to the pellet. Mixing was done until the pellet was dissolved.

The tubes were then put in an automatic thermal cycler. Initial denaturation was at 94°C for 10 min, 50 cycles for 1 min at 94°C, 63°C for 1 min, and 72°C for 1 min, and the final extension was for 10 minutes at 72°C. After the final PCR stage, 5 ?l of 10x gel loading solution was added to the sample. This was stored on ice until the process of agarose gel electrophoresis. The agarose gel electrophoresis was then done after which the viewing of the bands was done and the data was then collected.

Results According to the PCR results, there was no band in lane 4 as shown in the figure below In the negative control lane, there was no band or DNA fragment except there were bands below 50bp which were artifacts of the primers. The bands of 195bp were also observed There was also no band of 195bp at 0% control standard lane. Figure showing electrophoresis results Discussion No DNA fragment is expected to appear in the lane of negative control except bands at or below 50bpwhich are usually primers’ artifacts.

195bp bands show that there is CaMV35S promoter. Also the DNA fragments of 195bp should not appear in the lane of 0% control standard. A fragment of 195bp should appear in the lane of 2% control standard. The samples may or may not indicate a band at 195bp but for the soy bean sample, the band never appeared. Theoretically, an organic food product is required to be free from genetically modified foods. However, the definitions of organic vary. If a product shows that it is 100% organic, it is expected to have no band.

Non-organic foods products might probably have detectable levels of genetically modified food. Conclusion In conclusion, the findings never supported hypothesis that there is presence of GMOs in the soya beans. Further studies or research should be done to really ascertain that there is no GMOs in the soy beans. These results are unusual because it is expected that non-organic foods should have some traces of GMOs. This is according to literature. Bibliography Arakawa, T., D.K.X. Chong, and W.H.R.

Landridge. (1998). Efficacy of a food plant-based oral cholera toxin B subunit vaccine. Nature Biotechnology 16(3): 292. Clark, D. and L. Russell. (2000). Molecular Biology Made Simple and Fun. Vienna, IL: Cache River Press, pages 218-220. DG JRC.(1998). Directorate Generals European Commissions Joint Research Centre,Environment Institute, Consumer Protection & Food Unit. Screening method for the identification of genetically modified organisms (GMO) in food. FDA. (2000). U. S. Food and Drug Administration Center for Food Safety & Applied Nutrition.

Foods Derived from New Plant Varieties Derived through Recombinant DNA Technology. Online: http://vm.cfsan.fda.gov/~lrd/biocon.html