Les actualités du lycée Le Castel

Travail des 2ndes option euro SVT en anglais sur l'ADN

Par DAVID POULET, publié le jeudi 8 avril 2021 15:29 - Mis à jour le jeudi 8 avril 2021 15:29

Les 2ndes option euro SVT en anglais ont extrait de l’ADN à partir de fruits et légumes.

For this experiment, it is necessary to have: fruit or vegetable pieces, salt, dish soap and ethanol. The accessories you must have for this experiment are: a bowl, a spoon, a sterile gauze, a funnel and a test tube of course.

In a small bowl, we had to crush the banana to have porridge with a mortar.  After, we added two to three pinches of salt and a pipette of dish soap. It destroys the fat that surrounds the DNA, which protects it. We then let the "dough" rest for 10 minutes. Then, we needed a funnel, a compress, a test tube and a cotton ball. You have to put the funnel in the test tube and place the compress all around like a coffee filter. It is then necessary to place the cotton inside the funnel and to put the "dough" inside. We waited until only the liquid fell into the test tube.

The results: “a white filament of DNA”    “a small white circle”   “a cloud shape with small air bubbles”    “small particles visible to the naked eye”      “a white cloud-like substance”            “a translucent and gelatinous shape”           “a DNA jellyfish”

Attention : pour être précis, les filaments visibles sont une accumulation d’ADN et de protéines.