DNA Extraction from Banana (Class 10 Biology Project)

DNA Extraction from Banana 

Objective: To extract and observe the DNA from a banana using household materials.

 Materials Required: 

 1 ripe banana

 2 tablespoons water

 1 tablespoon dishwashing liquid (soap)

 ½ teaspoon salt

 Ziplock bag or bowl

 Coffee filter or clean cloth

 Small glass or transparent cup

 Cold rubbing alcohol (isopropyl alcohol) – keep it in the freezer for 30 min

 Spoon/stirrer

 Toothpick or stick (to lift DNA)

 Scientific Concept: 

 Soap breaks cell membranes.

 Salt helps DNA to clump together.

 Cold alcohol causes the DNA to separate and become visible.

Procedure:

1. Prepare the Strawberry Mixture

Place the strawberry into the ziplock bag.

Mash it thoroughly for 2 minutes to break the cells.

2. Make Extraction Solution

Mix water, salt, and dish soap in a cup.

Pour this solution into the bag with the strawberry.

Mash and mix gently for 1 more minute.

3. Filter the Mixture

Place the coffee filter over a glass.

Pour the strawberry mixture into the filter.

Let the liquid strain through (takes 5–10 minutes).

4. Add Cold Alcohol

Slowly pour cold rubbing alcohol down the side of the glass (equal volume to the filtered liquid).

Wait 2–3 minutes.

5. Observe DNA

A white, cloudy substance will begin to appear and rise — that’s DNA!

You can twirl a toothpick or stick to spool and lift the DNA.

 Observation:

• A cloudy, sticky layer appears at the boundary between the alcohol and fruit extract.

• It is stringy and can be pulled out using a stick — this is the visible DNA.

 Conclusion (Sample):

“In this experiment, we successfully extracted DNA from a banana. The soap broke down the cell membranes, salt allowed the DNA strands to clump, and alcohol made the DNA visible. This shows that DNA is present in all living things — even bananas!”

  

 Presentation Tips (for your project):

• Include pictures of each step (mashing, filtering, extracting).

• Add a drawing or labeled diagram of a plant cell and DNA strand.

• Display your real DNA sample (in a tube or jar) if possible.