Virginie Orgogozo
August 2007

Preparation of genomic DNA
(using DNAzol, cat. N 10503-027 or DN 127)

good if you want dead flies to be sent to you by mail


1. collect 20-30 flies in a 1.5mL microcentrifuge tube in 500uL DNAzol. Flies can be stored in DNAzol for a month at RT and for 10 months at 4C or -20C.
2. add 25uL RNAse (20mg/mL) and 5uL proteinase K (20mg/mL), mix well by inverting the tube multiple times.
3. grind flies with a disposable tissue grinder. Incubate at RT for 20min.
4. centrifuge at 10 000rpm for 10min.
5. transfer the viscous supernatant to a new tube. If you don't want any fly tissue left in your DNA prep, repeat steps 4 and 5.
6. add 250uL ethanol 100%. Mix well by inverting the tube 5-8 times. Incubate at RT for 2min. Make sure that the solution is homogenous.
7. centrifuge at 5 000rpm for 5min.
8. remove supernatant and wash with 500uL 75% ethanol: resuspend DNA in 75% ethanol by inverting the tube 3-6 times, and then centrifuge at 1 000rpm for 2min.
9. repeat the ethanol wash in 75% ethanol.
10. remove any alcohol from the bottom using a pipette. Air dry by storing the open tube for 1-2min (but no longer, otherwise it will be difficult to dissolve the DNA).
11. add 100uL 8mM NaOH (prepare this solution fresh every month from a 1M NaOH solution (10g in 250mL water), 1uL NaOH 1M in 124uL water). Wait 1min, then slowly pass the pellet through a pipette tip to dissolve the DNA.
12. Use 1uL for a 25uL-PCR-reaction.