Materials and Reagents

1. Mouse feces
   
2. Normal saline (about 5-10 ml per mouse, depending on the amount of feces) (e.g., Sigma-Aldrich)
   
3. Chloroform in methanol (2:1 by volume) (about 5-10 ml per mouse)
   

Equipment

1. Forceps suitable for picking up mouse feces
   
2. Sieve, coarse enough to hold back mouse feces
   
3. Optional: Flour sifter
   
4. 50-ml and 15-ml conical polypropylene tubes (one of each per mouse)
   
5. 15-ml glass tubes (one per mouse)
   
6. Tube stands
   
7. Analytical balance
   
8. Chemical fume hood
   
9. Potter-Elvehjem tissue grinder and drill
   
10. Centrifuge with rotor to hold 15-ml tubes (e.g., Beckman Coulter GS-6 with GH-3.8 swing bucket rotor or similar)
    
11. 22G 1½ hypodermic needles (two per mouse)
    
12. 5-ml syringes (one per mouse)
    

Procedure