TurboBlotting under Alkaline
Conditions: Southern Blot
Adapted from Chomczynsli, (1992). Analytical
Biochemistry 201: 134-139.
- Run 1 - 5 µg gDNA per lane, photograph
the gel with a fluorescent ruler.
- Soak gel in 0.25 M HCl for 15 minutes (hydrolyzes
long molecules into shorter ones for transfer).
- Rinse briefly in water.
- Soak gel in denaturing buffer 2 X 30 min. at
RT with gentle aggitation.
- Soak gel in transfer buffer for 15 min with gentle
aggitation. At the same time, wet and soak the Nytran membrane in dH 2
- Place the bottom half of the TurboBlotting tray
on a level bench (see diagram on next page).
- Place 20 sheets of dry absorbent paper (or appropriately
sized paper towels) inside the bottom half of the blotting tray.
- Place 4 sheets of dry blotting paper (or 3MM
paper) on top of the stack.
- Place one sheet of wet (soaked in transfer buffer)
blotting paper on top of the stack.
- Place the prewetted Nytran on top of the stack.
- Place the gel on top of the Nytra. Surround the
gel with parafilm if necessary. Make sure there are no air bubbles between
the gel and the Nytran.
- Wet the surface of the gel with a small amount
(about 1 ml) of transfer buffer and place 3 sheets of wet (transfer buffer)
blotting paper on top of the gel.
- Attach the top half of the buffer tray to the
bottom half. Add 125 ml of transfer
buffer to the tray.
- Start the transfer by connecting the gel stack
to the buffer using a wick that has been prewetted in transfer buffer.
Make sure the entire gel is covered with wick.
- Place a wick cover on top to prevent evaporation.
- Continue transfer for 1-4 hours.
- After the transfer is complete, remove the Nytran
and gel as a single unit. Mark the membrane with a VWR lab marker to indicate
which side has the DNA. Also, cut the gel and membrane along the bottom
to the wells and notch the top left corner of the Nytran to give it an
- Gently wash the membrane in 100 ml of 1X neutralizing
buffer for 5 min. (Use 5X stock solution)
- Place the Nytran, DNA side up, on a clean paper
towel and allow it to air dry for about 5 minutes. Then, cross-link the
DNA to the Nytran with 2.5 minutes of UV irradiation. The blot is ready
- Do not allow RNA to be transferred O/N; weak
signal due to hydrolyzed RNA.
- O/N transfer of DNA to Nytran is OK but not to
- Membranes can be dried for 15 min at 80 C but
only Nytran can be dried at RT.
- To strip a blot: 3 X 5 min. at 80° C in 0.5% SDS; 40 mM Tris-HCl, pH 7.8.
- 0.25 M HCl = 5.1 ml conc. HCl in 250 ml total
Reagents for Alkaline TuroBlotting
- Schleicher & Schuell membrane (0.2 µm
- 7 x 10 cm S&S # 77797
- 175.5 g = 3 M NaCl
- 16.0 g = 0.4 M NaOH
- 873 ml dH2O
(pH can be neutralized by CO2 - store air tight)
- 175.5 g = 3 M NaCl
- 0.32 g = 8 mM NaOH
- 0.63 g = 2 mM Sarkosyl
- 879 ml dH2O
5X Neutralizing Buffer:
1.0 M phosphate buffer, pH 6.8
- 79.5 g Na2HPO4
- 52.39 g anhydrous NaH2PO4
- (or 60.25 g NaH2PO4*H2O)
- bring to 1 L with water
1 X wet buffer-wick*
3X wet blotting paper*
1 X wet Nytran
1X wet blotting paper*
4 X dry blotting paper
20 X dry absorbent paper
* indicates prewet in transfer buffer
Lab Schedule Outlined
Lab Schedule In
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