Post on 25-Dec-2015
Finding genetical modified
contaminations (GMO) in groceries
by using gel electrophoresis & PCR
Biotechnologisches Gymnasium
Mettnau-Schule, Radolfzell
GMOGMO
Structure1. 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
corn
tofu
hamburger
lucky strike
dog food
polenta
potato crisps
rabbit food
bean sprouts
leaves of corn
11
3
2
(N = 23)
origin GMO primer
plant primer
result valid
1st analysis
Germany
tofu 1 - - - +1)
tofu 2 - - - +1)
soy meal - - - -
corn meal - + - +
hamburger - - - +1)
tobacco - - - -
dog‘s feed - - - +1)
popcornSeeberger
- + - +
negative c. - - - -2)
positive c. + + + +
Results of the investigation of GMO in food
1 = no chlorophyll
2 = DNA was digested
Results of the investigation of GMO in food2nd analysis GMO
primer plant
primer
result
valid
Germany
rabbit’s feedVitakraft
- + - +
biotofu, Edeka - - - +
fresh corn leaves Gottmadingen
- + - +
fresh corn - - - ?
bio-corn Seeberger - - - +
polenta Kattus - - - +
tortilla chips, Delvita - + - +
soy sprouts, bamboo garden
- - - +
tobacco, Lucky Strike
- - - +
Results of the investigation of GMO in food
USA 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. + + + +
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 samplesSolution : 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