Onion DNA Extraction

Materials

    Fresh onions

    Graduated cylinders (10ml and 100ml)

    Knife

    15 ml test tube

    Blender

    Test tube rack or 250 ml beaker

    Strainer

    Glass stirring rod

    Coffee filters

    Non-iodized salt

    Adolph's natural meat tenderizer

    Palmolive detergent

    Beaker

    Distilled water

    Ice cold 95% ethanol

Solutions

Detergent/salt solution:

    20 ml detergent

    20 g non-iodized salt

    180 ml distilled water

5% meat tenderizer solution:

    5 g meat tenderizer

    95 ml distilled water

Protocol

    Cut an inch square out of the center of 3 medium onions. Chop and place in a blender.

    Add 100 ml of detergent/salt solution.

    Blend on high 30 sec-1 minute.

    Strain the mixture into a beaker using a strainer with a coffee filter.

    Add 20-30 ml meat tenderizer and stir to mix.

    Place 6 ml filtrate in a test tube.

    Pour 6 ml ice cold ethanol carefully down the side of the tube to form a layer.

    Let the mixture sit undisturbed 2-3 minutes until bubbling stops.

    The DNA will float in the alcohol. Swirl a glass stirring rod at the interface of the two layers to see the small threads of DNA.

Modified from: "Isolation of DNA from Onion" Ellen Averill