1. Homogenize 50-100 fresh/frozen flies or embryos in a tissue grinder with 1.0 - 1.5ml homogenization buffer. Divide the homogenate into two 1.5ml microcentrifuge tubes.

2. Add 5µl of RNAse A (10mg/ml) and mix by inverting the tube several times. Incubate at 65^o C for 30 minutes.

3. Add 5µl of Proteinase K (10mg/ml) and mix by inverting the tube several times. Incubate at 55^oC for 30 minutes.

4. Add 75µl of 8M Potassium acetate. Place on ice for 45 minutes.

5. Centrifuge at 14,000 RPM at 4^oC for 10-15 minutes.

6. Transfer supernatant to a clean 1.5ml microcentrifuge tube making sure to AVOID THE PELLET.

7. Add 1/2 volume of saturated phenol and 1/2 volume of chloroform. Mix by inverting the tube several times. DO NOT VORTEX.

8. Centrifuge at 14,000 RPM & room temperature for 5 minutes.

9. Move the aqueous (top) layer to a clean tube and discard the bottom layer.

10. Repeat steps 7-9 two additional times or until no protein is left at interface.

11. Add 1 volume of chloroform, spin down and remove the supernatant as above.

12. Add 1000 µl of cold 100% ethanol to each tube, mix and place at -20^oC for 8 hours (or -80^oC for 15 minutes if DNA is needed immediately).

13. Centrifuge for 10-15 minutes at 4^oC and remove supernatant making sure not to disturb pellet.

14. Add 200-500 µl of cold 70% ethanol and spin as above for 2-5 minutes.

15. Remove as much of the ethanol as possible.

16. Let pellet air dry, then re-suspend in 25-50 µl of sterile nH₂0.

17. Combine samples and store at -20^oC