ABORATORY REPORT OF GMO TEST ON FOODS

User Rating: 0 / 5

Details

Hits: 14874

LABORATORY REPORT OF GMO TEST ON FOODS

Introduction

The term Genetically Modified Organisms (GMO) refers to animals or plants created by biotechnological techniques of gene splicing. GMO foods come from the merger of DNA from various species. It is yet to be proven whether GMO foods are safe, and increasing research has connected such foods with environmental damage and health concerns. Because of this reason, many developed countries have policies that require compulsory labelling of all GMO products at the very least. In fact, some issue bans on production and importation of GMO foods. The regulatory process of approval is asynchronous and complex, which necessitates testing for all agricultural products including food for GM content. GMO testing is for confirming the nature and identity of the product. This serves to determine the GMO content at each step in the chain of supply as to ensure it is compliant with labelling or importation regulations for GMOs. GMO test analysis is usually performed in a laboratory or in the field. Determination of the most suitable test method depends on the nature of the food sample, level of sensitivity required in the assay, as well as the proposed market for food.  Various tests may be performed for detection, identification, and quantification of GMO.

Materials and Methods

Materials

Doritos crisps (food to be tested), PCR samples, dye (preferably Orange G), PCR ruler, Test tubes (micro), Micropipettes possessing barrier tips (20-200 microlitres), Power supply, electrophoresis buffer, orbital shaker, centrifuge

Procedure

1. Genomic DNA was extracted from the food sample and a polymerase chain reaction (PCR) run in order to amplify the sequences of natural plant from DNA and GMO.
2. One of the PCR reactions utilized primers, which are specific to common plant primers. This verifies that the DNA extracted from the crisps was viable. This reaction always amplifies DNA, whether the sample is GM or not. Lanes 1 and 3 in this experiment show this amplification (Ahmed 2004).
3. In the next PCR reaction, primers that were specific to sequences usually seen in GM foods were used. This reaction only amplified DNA if the sample being tested contained GM, like in lane 4. If the food in question was not GM, the primers did not appear complementally to a sequence in the genomic DNA of the food being tested. The sample also failed to anneal, so there was no amplification of DNA.
4. Electrophoresis was done to check whether there was any DNA amplification or not. The electrophoresis of the products of PCR was done on a gel DNA was visualized as bands because the products had been stained.
5. To determine the sizes of the bands, the samples were mixed with a molecular weight ruler during electrophoresis as seen in Lane 5.
6. It was the absence or presence of certain sizes of fragments of DNA that would determine if the food being tested contained GMO or not. The bands of PCR products to be treated as important in this experiment were 200 bp for GM food primers and 455 bp for the natural plant primers. In particular, the promoter from the Doritos crisps was 200 bp and the terminator from other available controls was 224 bp.
7. A fresh tip of pipette was used to add Orange G dye to each sample. The food samples included:
8. Non-GMO food containing primers
9. Food for testing with primers
10. Non-GMO food containing GM primers
11. Food for testing with GM primers
12. Control DNA containing plant primers
13. Control DNA containing GM primers.

Results and Discussion

The table below summarizes that were obtained in this experiment.

The PCR markers of the molecular weight are 5 and include 1000 bp, 700 bp, 500 bp, 200 bp, and 100 bp. The test food did not generate a 200 bp band with GMO primer (lane 4). This means that the GMO status of the food being tested is negative.

When both the DNA band from the natural plant and that from the GMO come out clearly in the picture of the gel, then the food product would be said to contain GMO. Some samples, however, are not conclusive because the band of DNA failed to show in the picture. In such cases, the inference was that the PCR reaction did not take place successfully. The presence of the band of DNA indicated there contained GMO in the food sample being tested. In this experiment, it was determined that the Doritos crisps did not contain any GMO. Because the DNA band in the positive control showed while that the GMO band failed to come out, it can be safely concluded the Doritos crisps did not contain any GMO. If the GMO band came out alone and that in the GMO control failed, the results would not be considered conclusive (Nollet 2004).

Other information needed to confirm the GMO status of the food sample would be the reputation of the manufacturer and information contained on the leaflet that came with the food product. Information from bodies charged with assurance of quality can also be considered useful (Eede & Gruden 2011).

The results of the other five PCR reactions helped to support the result for the test food. The absence or presence of a band of size 200 bp in lane 5 shows whether the food being tested contained GMO. Nevertheless, the validity of such a result is dependent on the result obtained from the rest of the 5 PCR reactions. The determinant of the success of the extraction of the DNA from the plant primers is the positive control. The non-GMO control food, however, indicates a false positive finding, should it be present. In case the non-GMO control brings out a GMO-positive result, a DNA band in the second lane, the implication would be that the PCR reaction acquired contamination during some stage in the experiment. When the food being tested is also positive, the result cannot be trusted. The positive template or control always indicates false negative results. In cases where a positive template or control fails to amplify, the problem lies with the reaction and a negative result obtained from such a test food would not be trusted.

If the experiment were to be repeated, development of multiplex PCR techniques would yield better results. This is because such a practice has the ability to detect a variety of transgenic lines simultaneously (Bertheau 2012).

Conclusion

The Doritos crisps contain no GMO. Consequently, questions of whether they are safe for human consumption or not do not arise.

• Prev
• Next