Testing For Genetically Modified Foods

Visión general

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University

Genetic modification of foods has been a controversial issue due to debated concerns over health and environmental safety. This experiment demonstrates technical understanding of how food DNA is genetically identified, allowing for educated decision making about the safety and potential dangers of using genetically modified organisms (GMOs) in food supplies.

Polymerase Chain Reaction (PCR) is used to amplify food DNA to test for the presence of genetically modified DNA in food products. Presence of specific DNA bands is detected by using gel electrophoresis to pull extracted food DNA through a 3% agarose gel, a concentration dense enough to separate the bands of DNA containing the genetically modified DNA. Several controls are used in the electrophoresis procedure to ensure DNA is successfully extracted from test foods (plant primer), and to provide known examples of both genetically modified DNA (purchased genetically modified DNA) and non-genetically modified DNA (purchased certified non-GMO food control).

Procedimiento

1. Extraction of DNA From Food Samples

  1. Add 500 µL of purchased PCR mix matrix to each of the 2 screw-cap tubes using a transfer pipet or 200-1,000 µL adjustable-volume micropipette. Pipette up and down with the pipet between each aliquot to evenly mix the PCR matrix.
  2. Label one screw-cap tube “non-GMO” and the other “test”.
  3. Weigh out 0.5 g of certified non-GMO food and put it into the mortar.
  4. Add 2.5 mL of distilled water and grind with pestle for

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Resultados

After destaining, gels can be analyzed by looking at test food lanes (Table 3) to determine if the DNA bands for the 35S promoter and NOS terminator genes are present in the known locations on the gel. Placing the gel on a UV light box can help provide increased contrast (Figure 1). Alternatively, gels can be placed on white or yellow paper to provide a contrasting background to highlight DNA bands (Figure 2).

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Aplicación y resumen

Polymerase Chain Reaction (PCR) is used to amplify DNA, allowing for a wide range of DNA lab testing. One area of testing now possible with PCR is to identify GMOs by testing for presence or absence of the DNA sequences used in the genetic modification of food crops. Typically, a crop is genetically modified to confer an advantage against natural deterrents to ideal yields, e.g. pests (Figure 3), diseases, drought conditions (Figure 4), etc. Because the advantage is gained by in

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Tags
Genetically Modified FoodsDNA ModificationPolymerase Chain ReactionPCRGenetically Modified OrganismsGMOsDNA AmplificationGel ElectrophoresisAgarose Gel MatrixControl BandsDetecting Genetically Modified DNAGenetic Modification Process

Saltar a...

0:00

Overview

1:41

Principles of Identifying Genetically Modified Foods using PCR

4:44

Extraction of DNA from Food Samples

6:35

Setting up PCR

7:30

Electrophoresis of PCR Products

9:07

Results

10:10

Applications

12:15

Summary

Vídeos de esta colección:

article

Now Playing

Testing For Genetically Modified Foods

Environmental Science

89.3K Vistas

article

Identificación del árbol: Cómo utilizar una clave dicotómica

Environmental Science

81.0K Vistas

article

Encuesta sobre árboles: Método de muestreo de cuartos centrados en puntos

Environmental Science

49.2K Vistas

article

Uso de SIG para investigar silvicultura urbana

Environmental Science

12.4K Vistas

article

Pilas de combustible de membrana de intercambio protónico

Environmental Science

21.9K Vistas

article

Biocombustibles: Producción etanol a partir de material celulósico

Environmental Science

52.9K Vistas

article

Turbidez y sólidos totales en aguas superficiales

Environmental Science

35.7K Vistas

article

Oxígeno disuelto en aguas superficiales

Environmental Science

55.5K Vistas

article

Nutrientes en ecosistemas acuáticos

Environmental Science

38.7K Vistas

article

Medición de ozono troposférico

Environmental Science

26.3K Vistas

article

Determinación de NOx en los gases de escape de los automóviles mediante espectroscopia UV-VIS

Environmental Science

30.0K Vistas

article

Análisis de plomo en el suelo mediante espectroscopia de absorción atómica

Environmental Science

125.0K Vistas

article

Análisis de carbono y nitrógeno en muestras ambientales

Environmental Science

29.2K Vistas

article

Análisis de nutrientes del suelo: Nitrógeno, fósforo y potasio

Environmental Science

215.4K Vistas

article

Análisis de poblaciones de lombrices en el suelo

Environmental Science

16.4K Vistas

JoVE Logo

Privacidad

Condiciones de uso

Políticas

Investigación

Educación

ACERCA DE JoVE

Copyright © 2025 MyJoVE Corporation. Todos los derechos reservados