GMO or Organic, It is the question. RIE 2012
GMO or Organic, it is the question.
By The Chromatics
Dylan Baker, Carlos Martinez, Vanessa Mejia, Roberto Vargas,
Natasha Viener, Jaia Williams, Mr. Francesco Bocuzzi, Ms. Ana Cardenas,
Ms. Marva Nelson, Ms. Erica Flores, Mr. Andre Naranjo, and Dr. Yunqiu Wang
ABSTRACT
In this study, we investigated the impact of genetic technology to a major component of our
modern day life - food, which has been produced in a conventional manner or an organic
fashion. What we have found is that genetic engineering indeed has transformed the
genetic identity of some common food items we used to consume on a daily base. Genetic
modified elements have been identified in some of the food items collected from the
conventional food store. However, genetic modified elements were not detected in any food
items collected from the organic food store, indicating the “organic” nature of this kind of
foods have not been compromised by genetic technology.
INTRODUCTION
Food and Genetic Modification
Our research program was set up to investigate the impact of genetic technology to a
major component of our modern day life, food. Food is important to our everyday life because it
gives us the energy we need to perform our everyday activities. Genetic engineering has made a
huge impact on our food community. Genetic engineering has given us the ability to grow crops
faster, make them more resistant to disease, cold, draught and most importantly, pest. For
example, Bacillus thuringiensis (Bt) is a bacteria that produces toxins which can make holes on
the stomach lining of pests, eventually killing them1. When crops are introduced with the gene
that creates the toxin, the pests that eat these crops will get holes in their stomach lining and die.
This means farmers get more food harvested being able to feed more people. This kind of foods
containing products from genetically modified organisms is known as GMO food. A GMO is an
organism whose genes have been altered with new traits from other organisms, in many cases
from bacteria.
There are many corn, cotton, and soy crops that are genetically modified in the United
States. For example, approximately 91 percent of soy beans are genetically engineered and
about 85 percent of corn is genetically modified, according to the Center for Food Safety. GM
soybeans are now planted in nine countries in the USA, and they take up more than 60 million
hectares2. Soy and corn are two most common crops that have been genetically modified because
there is a very high demand for byproducts of these plants, like in the case of high fructose corn
syrup and animal feed, etc. Bt corn was engineered by introducing a Bt gene into the genome of
the crop. The Bt gene product protects the crops from the pest. The promoter (CAMV35S) and
terminator (NOS) are used as primers to identify the presence of the Bt gene. Whatever plant
contains the Bt gene means that it has been genetically modified1 .
To detect the presence of Bt gene, we used the Polymerase Chain Reaction, also known
as PCR method, and the PCR products were analyzed with gel electrophoresis method in our
study.
Organic Farming: An Alternative to GM
To experience an alternative way of food production, we also made a visit to an organic farm.
Organic farming is a way of agriculture that does not utilize synthetic fertilizers, chemically
based pesticide and herbicide or GM crops3 . The farm was built to mimic a forest, so instead of
rows and rows of food, there were different levels of plants that were meant to help each other.
For example, because the soil in Florida is not very nutrient rich and low on organic matter, they
let the weeds grow, something they called “biomass”. Then they cut them down and let them
decompose to later be used as fertilizer for the other plants.
Research Focus
Our group’s aim is to test how much genetic engineering has encroached on the world’s food
supply. We are studying genetically modified organisms and comparing those to foods found in
organic food stores and conventional food stores in order to get a sense of how truly organic
foods from these stores are, and how much genetic technology has influenced our food source.
We hypothesize that food samples collected from the organic food store will be free of genetic
modified organism, while food samples collected from the conventional store will contain
genetic modified organisms.
METHODS
Sample Collection and Preparation
First, we collected food samples (Table 1) which are organic and conventional foods. Then we
cut a piece of the food, weighing 2 to 2.5 grams. Then we got a mortar and pestle and ground up
the food with 5 ml of water into slurry. Then we pipetted 50 µl of our paste into a tube and we
added 250 µl of Instagene (extracts the DNA). Then we vortexed for approximately 10 seconds
then heated the sample to 95° C for 5 minutes. Then we centrifuged it at 13,000 rpm for 5
GMO or Organic, It is the question. RIE 2012
minutes. Next we pipetted 10 µl from the top clear layer (supernatant containing DNA) into PCR
tubes.
Table 1. Summary of food samples used and category (organic or conventional)
Food Sample
Super Food Odwalla Bar
365 Popcorn
Tex-Mex Veggie Burgers
Fruit and Nuts Bar
Wise Popcorn
Morningstar Veggie Burgers
Goya Areps
Banquet Sausage
Organic or Conventional
Organic
Organic
Organic
Conventional
Conventional
Conventional
Conventional
Conventional
Utilizing Genetic Tools to Determine GM
Polymerase Chain Reaction
PCR stands for Polymerase Chain Reaction. PCR is used to amplify specific segments of DNA
into large quantities, using the promoter (CAMV35S) and terminator (NOS) as primers to
identify the presence of the Bt gene. The reaction involves DNA polymerase which is an enzyme
that creates new strands of DNA. There are 3 main steps which repeat 40 times. The 1st step is
denaturing where it breaks strands apart at around 94°C. The 2nd step is annealing where the
primers stick together at around 40-65˚C. The last step is extension where new nucleotides are
added at around 72°C. After the PCR reaction is complete, the products can be visualized on an
agarose gel.
Gel electrophoresis
Gel Electrophoresis is the process by which electric current is used to separate DNA, which
stands for deoxyribonucleic acid. In nature, DNA is negatively (-) charged, so it is attracted to
the positive (+) side. We load the DNA into wells in the agarose gel. The agarose in the gel
solution has a mesh like structure with holes of various sizes. This structure sorts out the DNA
based on size. The small pieces run faster and farer than the big pieces of DNA. Buffer in
electrophoresis is it contains ions that allow electricity to pass through the apparatus, unlike
distilled water that does not contain salt or ions to conduct electricity. We also load a ladder with
the samples which contain fragments of DNA that come in different sizes in base pairs. We can
use the ladder to tell the size of the PCR products. The gel was run at 100 volts for 45 minutes.
Then we view the gel under the UV light to determine the size of the PCR products.
RESULTS
Below are the gel images showing the results of the PCR reactions. A molecular weight
(MW) was run alongside the PCR reactions to be used as a ruler to determine the size of the
products. Samples in each lane are indicated on the right side of each gel and are indicated with
the following abbreviations for the type of food and primers used: Organic (Org.), Conventional
(Con.), Plant primers (P) and GMO primers. Band sizes for the MW marker are 100 bp, 200 bp,
455 bp, 700 bp, and 1,000 bp (bottom to top). As a reminder, we are looking for two distinct
products: plant gene (455bp) which are highlighted with green boxes and the GM gene (200bp)
which is highlighted with a red box. The results of the gels are summarized in Table 2.
LANE 1: MW Marker
LANE 2: Org. veggie burger, P
LANE 3: org. veggie burger, G
LANE 4: org. fruit & nut bar, G
LANE 5: org. fruit & nut bar, P
LANE 6: conv. veggie burger, G
LANE 7: conv. veggie burger, P
LANE 8: Non-GMO Oats, P
LANE 9: Non-GMO Oats, G
LANE 10: MW Marker
LANE 1: MW Marker
LANE 2: conv. popcorn P.
LANE 3: conv. Popcorn GMO
LANE 4: conv. Fruit & nut bar P
LANE 5: Conv. Fruit & nut bar GMO
LANE 6: org. popcorn P
LANE 7: org. popcorn GMO
LANE 8: Non-GMO Oats, P
LANE 9: Non-GMO Oats, G
LANE 10: MW Marker
GMO or Organic, It is the question. RIE 2012
LANE 1: MW Marker
LANE Conv. Arepas, P
LANE 3: Conv. Arepas, G
LANE 4: Conv. Arepas, P
LANE 5: Conv. Arepas, G
LANE 6: MW Marker
LANE 1: MW Marker
LANE 2: Conv. Sausage, P
LANE 3: Conv. Sausage, G
LANE 4: Conv. Popcorn, G
LANE 5: Conv. Popcorn, P
LANE 6: Conv. Sausage, P
LANE 7: Conv. Sausage, G
LANE 8: + Control GMO DNA, G
LANE 9: + Control GMO DNA, P
LANE 10: MW Marker
Table 2. Summary of PCR products detected from organic and conventional food samples.
Positive results are indicated by a (+) and the absence of a particular band is indicated by a (-).
Food Sample
365 popcorn (Organic)
Odwalla bar (Organic)
Pregger’s Veggie Burger(Organic)
Non-GMO Oats
Fruit and Nut Bar
Wise popcorn
Morningstar Veggie Burger
GOYA Arepas
Banquet Sausages
GMO-Positive Control
Plant
GMO
+
+
+
+
+
+
+
+
+
DISCUSSION
Our results show that the food from Whole Foods was really organic because of the
absence of GM DNA. These foods are the 365 Popcorn and the non GMO oats (used as a
negative control). Our results in the GMO column also show that the food from Publix was
conventional and did actually contain GM genes. These foods were Morningstar Veggie Burger,
Wise popcorn, Banquet Sausages and GMO positive control. The foods that did not have any
results were the Odwalla bar, Fruits and Nuts Bar, Preggers Veggie Burger and the GOYA
Arepas. The possibilities for why there were no results were that the DNA was processed so
much that the DNA was destroyed. Another possibility is that our reaction had been
compromised. This proves that there are genetically modified foods in the public stores without
any label or warning.
While the effects of genetically modified organisms are not fully understood, there is no
doubt that they have become incorporated into our daily lives more and more over time. At first,
it seems that organic farming is completely different from growing genetically modified crops
but they are actually different paths toward the same goal: providing enough food to feed a
growing population with limited space. Organic farming is becoming more popular, but this
method has its own challenges, such as the scale and cost. This study has shown that many foods
that are present in our everyday lives contain GM plant materials, mostly unknown to the
American population. Science continues to meet the challenges of an expanding human race, and
aims to do so in a way that is healthy for not only people, but also for the environments that all
creatures inhabit on the Earth.
REFERENCES
1. Biotechnology Explorer GMO investigator Kit, Bio-Rad.
2. Bren, Linda. 2003. "Genetic Engineering: The Future of Foods?" FDA. 2 Mar. 2009
<www.fda.org>.
3. Lohr, Luanne. 2001. Factors affecting international demand and trade in organic food
products. Changing Structure of Global Food Consumption and trade/ WRS-01-1.
USDA Economic Research Service. Pp 67 – 79.