WHITE LAB – SOUTHERN
BLOTTING PROTOCOL
SOLUTIONS
Lysis
Buffer
0.1
M Tris, pH 8.0
0.2
M NaCl
5
mM EDTA
0.2%
w/v SDS
200
mg/ml proteinase K
TE
Buffer
10
mM Tris-Cl, pH 7.4
1
mM EDTA, pH
Denature
Neutralize
20X
SSC
Membrane
Wash
WHITE LAB – SOUTHERN
BLOTTING PROTOCOL
GENOMIC DNA EXTRACTION
1. Cut mouse tails, place in tubes, and add 0.5 ml of fresh
lysis buffer [0.1M Tris, pH 8.0; 0.2M NaCl; 5mM EDTA; 0.2% w/v SDS; 200 mg/ml proteinase K] to each tube
2. Digest overnight in 55ºC waterbath
3. Spin tubes for 20 minutes at full speed
to pellet tail debris
4. Remove supernatant (avoid hair &
debris) to 24-well plates containing 0.75 isopropanol
Use wide-orifice tips to avoid
shearing the DNA.
5. Leave plates on rocker for 40+ minutes,
until DNA precipitates are visible
6. Use wide-orifice tips to remove
precipitated DNA to tubes containing 0.5 ml 70% EtOH
7. Spin tubes for 10 minutes at full speed
8. Use gel loading tips to aspirate pellet
– make sure pellet is dry
9. Add 100-250ml TE to each tube
10. Incubate overnight in 55ºC waterbath
11. Store at 4ºC
DIGESTION OF GENOMIC DNA
12. Aliquot 15ml of genomic DNA into fresh
labeled tubes
13. Make up appropriate restriction enzyme
digestion and add to tubes
14. Incubate overnight in 37ºC waterbath
GEL ELECTROPHORESIS
15. Run samples on 0.8% agarose gels at ~150V for approximately 3-4 hours
16. Denature gels for 45 minutes on rocker in denature
solution [1.5M NaCl; 0.5M NaOH]
17. Neutralize gels for 45-60+ minutes on rocker in neutralizing
solution [1M Tris; 1.5M NaCl; pH 7.4]
18. Set up transfer using 10X SSC and Hybond
– transfer overnight
19. Mark well positions on membranes
20. Cross-link the DNA to the membranes
using the UV crosslinker
21. Stain for 5 minutes in water with a little
EtBr
22. De-stain in water for 20 minutes and
check under UV to verify transfer
HYBRIDIZATION AND PROBE
SYNTHESIS
23. Prehyb [30 ml of 20X SSC; 2.5 ml of 20% SDS; 50 ml of
formamide; 5 ml of 100X Denhardts (or 10 ml of 50X); 12.5 ml of H2O;
1 ml of herring sperm] for 4-6 hours in 42ºC shaking waterbath in covered
containers – place 1 ml of herring sperm DNA in heatblock for 5 minutes,
transfer to ice for 5 minutes, then add to prehyb solution
Need approximately 100 ml of prehyb to prehyb and probe 4
membranes, 50 for prehyb and 20-30 for hybridization
24. Make probe according to NEB nick translation kit and purify
with Nick columns or Qiagen Nucleotide Removal kit
25. Place probe on heatblock for 5 minutes;
transfer to ice for 5 minutes
26. Add probe to 20-30 ml of prehyb mixture;
mix thoroughly
27. Add membranes to container with mixture;
make sure they aren’t sticking together
28. Hybridize overnight at 42ºC in
shaking waterbath
29. Add membrane wash [2X SSC; 0.5% SDS] to
fresh containers
30. Remove membranes from probe solution
and add to wash containers
31. Wash twice for 20 minutes in 42ºC
shaking water bath
32. Let membranes dry on Whatman paper
33. Wrap in Saran Wrap and expose overnight on autorad cassette
or PhosphorImaging cassette
34. Decant probe into waste tube or save in
falcon tube
35. Develop film