GMO
Finding genetical modified
contaminations (GMO) in groceries
by using gel electrophoresis & PCR
Biotechnologisches Gymnasium
Mettnau-Schule, Radolfzell
Structure
1. Experiment design
2. Grocery samples tested
3. Results of the investigation of
GMO food
- Germany ( 1st and 2nd analysis)
- USA
4. Conclusion
5. Suggestions and next steps
Experiment design
1)Sample preparation
2)PCR
3)Gel electrophoresis
4)Analysis
Grocery samples
Grocery samples (N = 23)
corn
3
tofu
hamburger
lucky strike
dog food
11
polenta
2
potato crisps
rabbit food
bean sprouts
leaves of corn
Results of the investigation of GMO in food
origin
GMO
primer
plant
primer
result
valid
1st analysis
Germany
1 = no
chlorophyll
tofu 1
-
-
-
+1)
tofu 2
-
-
-
+1)
soy meal
-
-
-
-
corn meal
-
+
-
+
hamburger
-
-
-
+1)
tobacco
-
-
-
-
dog‘s feed
-
-
-
+1)
popcorn
Seeberger
-
+
-
+
negative c.
-
-
-
-2)
positive c.
+
+
+
+
2 = DNA was
digested
Results of the investigation of GMO in food
2nd analysis
GMO
primer
plant
primer
result
valid
rabbit’s feed
Vitakraft
-
+
-
+
biotofu, Edeka
-
-
-
+
fresh corn leaves
Gottmadingen
-
+
-
+
fresh corn
-
-
-
?
bio-corn Seeberger
-
-
-
+
polenta Kattus
-
-
-
+
tortilla chips, Delvita
-
+
-
+
soy sprouts, bamboo
garden
-
-
-
+
tobacco, Lucky
Strike
-
-
-
+
Germany
Results of the investigation of GMO in food
GMO
primer
plant
primer
results
valid
America’s choice
corn starch
-
+
-
+
America’s choice
muffin mix
-
+
-
+
All natural corn
starch
Agro Pure corn
starch
Quaker, corn meal
-
-
-
+
-
-
-
+
-
+
-
+
Aunt Jamina corn
meal mix
-
+
-
+
Jiffy corn muffin mix
-
+
-
+
fresh corn leaves
-
+
-
+
fresh corn
-
+
-
+
negative c.
-
+
-
+
positve c.
+
+
+
+
USA
Conclusion
Result
No GMO detected
Food was not genetically modified
Standard
Experimental design worked
GMO Primer
Only covers 85% of the organism
Plant Primer
Could not be detected in all samples
Solution : sample mill for disintegration
Suggestions and next steps
- DNA is digested without sample buffer , even when it‘s boiled : Buffer contains complexing
substances for Ca2+ and Mg2+
- Gels with 3 % (w/v) agarose : tends to keep air bubbles
- High concentration of agarose and buffer : the gel swells
- Problem: the wells will become smaller and smaller : difficult to load - remove comb just before
loading
- PCR is not influenced by any mistakes
- For electrophoresis: put samples + control samples of the same primer together in 1 line
– you can save space!
- Two combs fits in one gel – that saves space as well !
=> For statistic purpose : sent us more samples !!!
Thank you for your attention