Placing the gel on the Southern apparatus

and preparing the nylon membrane.

Once the gel has been denatured and neutralized, it is ready for Southern transfer.
The gel is carefully inverted.  When running a gel, the DNA is closer to the bottom. By inverting the gel, the DNA has less far to move through the gel when being transferred to the nylon membrane.
The gel is inverted so the wells are now facing down, towards the filter paper wicks.
The gel is centered on the filter paper wick, and any air bubbles are gently pushed out.
Meanwhile, the nylon membrane is prepared by wetting it in distilled water.
The membrane is separated from the protective paper.
Once the membrane is wet, it is ready to place on the gel.