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Updated: Dec 27, 2025
Cell-Free DNA Integrity Analysis in Urine Samples
Published on: January 5, 2017
A revalidation and critique of assumptions about urinary sample collection methods, specimen quality and
Linda Collins1, Sanchutha Sathiananthamoorthy2, Jennifer Rohn2
1School of Nursing, Kingston University, Frank Lampl Building, Kingston Hill Campus, London, UK. l.collins@sgul.kingston.ac.uk.
Introduction And Hypothesis:
Midstream urine (MSU) is key in assessing lower urinary tract syndrome (LUTS), but contingent on some assumptions. The aim of this study was to compare the occurrence of contamination and the quality of substrates obtained from four different collections: MSU, catheter specimen urine (CSU), a commercial MSU collecting device (Peezy) and a natural void. Contamination was quantified by differential, uroplakin-positive, urothelial cell counts.
Methods:
This was a single blind, crossover study conducted in two phases. First, we compared the MSU with CSU using urine culture, pyuria counts and differential counting of epithelial cells after immunofluorescence staining for uroplakin III (UP3). Second, we compared the three non-invasive (MSU, Peezy MSU™, natural void) methods using UP3 antibody staining only.
Results:
The natural void was best at collecting bladder urinary sediment, with the majority of epithelial cells present derived from the urinary tract. CSU sampling missed much of the urinary sediment and showed sparse culture results. Finally, the MSU collection methods did not capture much of the bladder sediment.
Conclusion:
We found little evidence for contamination with the four methods. Natural void was the best method for harvesting shed urothelial cells and white blood cells. It provides a richer sample of the inflammatory exudate, including parasitised urothelial cells and the microbial substrate. However, if the midstream sample is believed to be important, the MSU collection device is advantageous.
Insights
The natural void method best captures bladder sediment for assessing lower urinary tract syndrome (LUTS). While midstream urine (MSU) collection devices offer advantages, natural voiding provides a richer sample of urothelial cells and inflammatory markers.
Area of Science:
- Urology
- Clinical Diagnostics
- Microbiology
Background:
- Midstream urine (MSU) is commonly used for diagnosing lower urinary tract syndrome (LUTS).
- The accuracy of MSU relies on assumptions about sample quality and contamination.
- Alternative urine collection methods require evaluation for improved diagnostic yield.
Purpose of the Study:
- To compare contamination rates and substrate quality across four urine collection methods: MSU, catheter specimen urine (CSU), a commercial MSU device (Peezy), and natural void.
- To determine the optimal method for collecting urothelial cells and microbial substrates for LUTS assessment.
Main Methods:
- A single-blind, crossover study comparing MSU with CSU using urine culture, pyuria counts, and uroplakin III (UP3) immunofluorescence staining.
- A second phase compared non-invasive methods (MSU, Peezy MSU, natural void) using UP3 staining.
Main Results:
- Natural voiding yielded the most bladder urinary sediment, with cells primarily from the urinary tract.
- CSU sampling resulted in missed sediment and sparse cultures.
- MSU collection methods captured limited bladder sediment.
Conclusions:
- Natural voiding is superior for collecting shed urothelial cells and white blood cells, offering a richer inflammatory exudate sample.
- All four methods showed minimal contamination.
- For midstream sample importance, the MSU collection device is advantageous.
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