Experimental Practice Detection of genetically modified DNA-components in food by polymerase-chain-reaction (PCR) Introduction

Aims of the experiment Qualitative detection of a genetical modification in food. Detection of modifications caused by - the promoter of the cauliflower mosaik virus (CaMV) - the terminater of nopalin synthesis (NOS) in agrobacterium tumefaciens Both sequences are often used for regulation of foreign genes in genetically engineered soy beans and corn.

Step by Step procedure Step: DNA-Isolation - out of control soy beans without genetically modified components (-GMO) - out of test food (T)

Step by Step procedure 2. Step: PCR As control for existing plant material in food and for a successful PCR:  Amplification of a gene coding for a protein in the fotosystem II with length of 455 Bp As two characteristic DNA-sequences for a genetically modification in food:  Amplification of a gene a) from CaMV-promoter with 203 Bp b) from NOS-terminator with 225 Bp

Cycler time program 40 Cycles 60``, 94 °C Denaturation Completing 60``, 94 °C Denaturation 40 Cycles 120``, 94 °C Denaturation 60``, 59 °C Annealing 120``, 72 °C Elongation

Step by Step procedure Step: Electrophoresis and evaluation Detection of PCR-products by agarose-gel-electrophoresis DNA-staining and evaluation of the gel Contains your test food foreign DNA?

Expected results PS II gene sequence (455 Bp) NOs sequence (225 Bp) CaMV sequence (203 Bp) 1 2 1 2