A method for collecting and preserving urine protein in household

Abstract

Urine is a good source for identifying novel biomarkers. Urine samples should be comprehensively collected and preserved. Therefore, we established an urimem method in which urinary proteins were adsorbed onto membranes, following which the membranes were dried and stored in a vacuum bag. This method is economical, and samples can be stored at room temperature. In addition, it is more suitable in laboratories. For collecting urine samples of patients at home, a simple, easy to use method is necessary. The kit used in this method comprises a filter coupled with a syringe. The syringe was used as a pressure generator to pass the urine through the filter, which contained two membranes. The polyvinylidene fluoride (PVDF) membrane was used for isolating cells, and the nitrocellulose (NC) membrane was used for adsorbing proteins. After adsorption, the NC membrane was placed in a sealed plastic bag with a drying agent and stored at room temperature for 10 days. To assess the stability of the urimem method, SDS-PAGE and LC-MS/MS were performed to qualitatively and quantitative analyze the proteins that were eluted from the membrane. The results showed that the method was reproducible. This method is highly accessible and convenient for patients to collect urine by themselves at home. Furthermore, it facilitates sample transportation and may be beneficial for identifying research biomarkers in urine.