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 samplesGrocery 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 

validGermany        

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 

validAmerica’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