The exact causes of chronic kidney failure are unknown, although the debilitating loss of healthy kidney tissue may be a natural endpoint for several readily recognizable conditions, including advanced dental disease and a variety of kidney infections, inflammations and obstructions.
Sodium chloride was needed to ensure the proteins in the cell aren't separated from the rest of the solution with the DNA. Okay, the person above does not understand Chemistry nor the English language. The sodium chloride, NaCl, is a polar molecule, which would help separate an emulsion of two layers in an acid-base extraction. Since NaCl is polar, it would be easily dissolved into the solution and tie up the different layer molecules.
The overall function of salt and ethanol/ isopropanol is to precipitate DNA from the solution. The salts neutralize the negative charge of the negatively charged phosphate in DNA and the isopropanol /ethanol removes the hydration shell of H 2 O molecules around the phosphate. The total effect is that the DNA molecules can come together due to neutralization of charge and removal of water that leads to the precipitate from the solution.