proteins are valuable biomarkers because they provide a direct indication of a biological state or condition, and they can be assayed in body fluids. Urine has roused great interest in recent years as a source of biomarkers, as it is an ultrafiltration of plasma, its collection is minimally invasive and samples are easy to handle. However, certain features of the sample, such as the diluted protein concentration and high salt content, present their own unique challenges for protein analysis. In this brief communication we compare four methods of protein extraction from urine, and conclude that acetone precipitation yields the highest protein concentration, as well as the best resolution of protein spots in 2D electrophoresis. This method of extraction can be easily performed in any lab without the need for commercial kits.