Simple SummaryIn the field of cancer, body fluids such as urine are gaining interest for non-invasive cancer detection and screening. To enable home collection, sample shipment, and sample storage at ambient temperatures, the addition of preservatives is critical. In this study, we evaluated the performance of a recently developed preservative, UAS™, for the preservation of urinary analytes in oncology applications. We demonstrated that UAS™ preserves host cell integrity and cell-free DNA and prevents bacterial overgrowth under conditions encountered with remote collections. Additionally, UAS™ is compatible with commercially available urinary analyte isolation kits. The preservative facilitates urine collection in the comfort and privacy of the patient’s home, making cancer screening programs more accessible and lowering the burden on healthcare workers.AbstractLiquid biopsy is a revolutionary tool that is gaining momentum in the field of cancer research. As a body fluid, urine can be used in non-invasive diagnostics for various types of cancer. We investigated the performance of UAS™ as a preservative for urinary analytes. Firstly, the need for urine preservation was investigated using urine samples from healthy volunteers. Secondly, the performance of UAS™ was assessed for cell-free DNA (cfDNA) and host cell integrity during storage at room temperature (RT) and after freeze-thaw cycling. Finally, UAS™ was used in a clinical setting on samples from breast and prostate cancer patients. In the absence of a preservative, urinary cfDNA was degraded, and bacterial overgrowth occurred at RT. In urine samples stored in UAS™, no microbial growth was seen, and cfDNA and cellular integrity were maintained for up to 14 days at RT. After freeze-thaw cycling, the preservation of host cell integrity and cfDNA showed significant improvements when using UAS™ compared to unpreserved urine samples. Additionally, UAS™ was found to be compatible with several commercially available isolation methods.