1. Cell Lysis:

- Gather your materials which includes a sample of cells (plant or animal tissue), salt, liquid dishwashing soap, and a DNA extraction buffer (TE buffer or Tris-EDTA buffer).

- Place a small piece of the tissue sample in a mortar and pestle or a small container with a lid.

- Add a small amount of salt to the sample (about 1/4 teaspoon per 1 gram of tissue).

- Add a few drops of liquid dishwashing soap to the mixture and grind or mash the tissue thoroughly.

- This step breaks open the cell membranes, releasing the DNA.

2. Protein Precipitation:

- Transfer the lysate (the mixture of broken cells) to a centrifuge tube.

- Add a volume of cold DNA extraction buffer equal to the volume of the lysate. Mix thoroughly.

- The DNA extraction buffer contains detergents that help dissolve cell membranes and proteins, as well as a salt solution that helps to precipitate proteins (including histones associated with DNA) out of the solution.

- The proteins form a clump and separate from the DNA.

3. DNA Precipitation:

- Centrifuge the mixture for a few minutes at high speed (around 12,000–15,000 rpm).

- This will cause the precipitated proteins and cell debris to form a pellet at the bottom of the tube, leaving the DNA in the supernatant (the liquid above the pellet).

4. DNA Collection:

- Carefully remove the supernatant, which contains the DNA, into a new tube.

- Avoid transferring any of the pellet, as it contains mostly protein and cellular debris.

- The DNA is now in a relatively pure form, free from most cellular components and proteins.

Ethanol Extraction:

1. DNA Precipitation:

- To the tube containing the DNA solution from the salt soap extraction, add an equal volume of cold 95%-100% ethanol.

- Mix gently by inverting the tube several times. Do not vortex, as this can shear the DNA.

- The DNA will start to precipitate out of the solution as a white, stringy mass.

2. DNA Washing:

- Centrifuge the mixture for a few minutes at high speed (around 12,000–15,000 rpm).

- The DNA will form a pellet at the bottom of the tube. carefully remove the supernatant (the ethanol solution) without disturbing the pellet.

3. DNA Drying:

- Gently rinse the DNA pellet with cold 70% ethanol to remove any residual salts.

- Centrifuge briefly to collect the DNA at the bottom of the tube.

- Carefully remove the ethanol without disturbing the pellet.

- Allow the DNA pellet to air dry for a few minutes.

4. DNA Resuspension:

- Add a small amount of DNA extraction buffer (TE buffer or Tris-EDTA buffer) to the tube containing the DNA pellet.

- Use a micropipette to gently resuspend the DNA by pipetting up and down until it is completely dissolved.

- The DNA is now ready for further analysis, such as PCR, gel electrophoresis, or other molecular biology techniques.

Both methods aim to disrupt the cell membrane, release DNA, and then separate the DNA from other cellular components through precipitation and centrifugation. They provide a simple and cost-effective way to extract DNA for basic experiments and educational purposes.