Extracting DNA from Cheek Cells

DNA Extraction

Procedure

Step 1. Swish 10 mL saline solution in mouth to dislodge buccal epithelial cells

Step 2. Expel into cup

Step 3. Using 1.5 mL expelled solution, centrifuge for 3 minutes at 14,000 rpm

3 min @ 14000 𝘨

Step 4. Carefully remove supernatant, leaving cell pellet undisturbed

Step 5. Break up pellet by vortexing

Step 6. Add 500 µL 10% chelex solution. Chelex resin will settle out very quickly so it is best to invert the tube frequently when pipetting

Step 7. Heat at 56°C for 10 minutes, vortexing halfway through

10 min @ 56 °C

Step 8. Heat at 100°C for 5 minutes

5 min @ 100 °C

Step 9. Cool on ice for 3 minutes

3 min @ -20 °C

Step 10. Centrifuge at 8,000 rpm for 5 minutes

5 min @ 8000 𝘨

Step 11. Transfer 300-400 µL supernatant to new tube.

Target volume

Unit

Step 1. Add sodium chloride to a falcon tube.

Sodium Chloride

0.9 g

Step 2. Bring final volume to 100 mL with water.

Target volume

Unit

Step 1. Prepare ingredients.

Chelex 100 Sodium Form

1 g (10 % w/v)

Step 2. Bring final volume to 10 mL with water.