How does restriction fragment length polymorphism (RELP) technique work?

In this technique:

1. DNA is first cut into fragments using restriction endonuclease enzymes that recognize specific sequences. 
2. The DNA fragments are separated by size using agarose or polyacrylamide gel electrophoresis.
3. The different-sized DNA fragments are denatured into single strands using sodium hydroxide (NaOH).
4. The single-stranded DNA fragments are transferred onto a nitrocellulose membrane through electro-blotting or capillary blotting.
5. The nitrocellulose membrane is fixed by autoclaving and then blocked with casein or bovine serum albumin to prevent non-specific binding.
6. The labeled RFLP probe is hybridized with the complementary DNA on the membrane and the resulting bands are visualized using autoradiography.